perlapi

PERLAPI(1) Perl Programmers Reference Guide PERLAPI(1)

NAME

perlapi - autogenerated documentation for the perl public API

DESCRIPTION

This file contains the documentation of the perl public API generated
by embed.pl, specifically a listing of functions, macros, flags, and
variables that may be used by extension writers. The interfaces of any
functions that are not listed here are subject to change without
notice. For this reason, blindly using functions listed in proto.h is
to be avoided when writing extensions.
Note that all Perl API global variables must be referenced with the
"PL_" prefix. Some macros are provided for compatibility with the
older, unadorned names, but this support may be disabled in a future
release.
The listing is alphabetical, case insensitive.

"Gimme" Values

GIMME A backward-compatible version of "GIMME_V" which can only
return "G_SCALAR" or "G_ARRAY"; in a void context, it returns
"G_SCALAR". Deprecated. Use "GIMME_V" instead.
U32 GIMME
GIMME_V The XSUB-writer’s equivalent to Perl’s "wantarray". Returns
"G_VOID", "G_SCALAR" or "G_ARRAY" for void, scalar or list con-
text, respectively.
U32 GIMME_V
G_ARRAY Used to indicate list context. See "GIMME_V", "GIMME" and
perlcall.
G_DISCARD
Indicates that arguments returned from a callback should be
discarded. See perlcall.
G_EVAL Used to force a Perl "eval" wrapper around a callback. See
perlcall.
G_NOARGS
Indicates that no arguments are being sent to a callback. See
perlcall.
G_SCALAR
Used to indicate scalar context. See "GIMME_V", "GIMME", and
perlcall.
G_VOID Used to indicate void context. See "GIMME_V" and perlcall.

Array Manipulation Functions

AvFILL Same as "av_len()". Deprecated, use "av_len()" instead.
int AvFILL(AV* av)
av_clear
Clears an array, making it empty. Does not free the memory
used by the array itself.
void av_clear(AV* ar)
av_delete
Deletes the element indexed by "key" from the array. Returns
the deleted element. If "flags" equals "G_DISCARD", the element
is freed and null is returned.
SV* av_delete(AV* ar, I32 key, I32 flags)
av_exists
Returns true if the element indexed by "key" has been initial-
ized.
This relies on the fact that uninitialized array elements are
set to &PL_sv_undef.
bool av_exists(AV* ar, I32 key)
av_extend
Pre-extend an array. The "key" is the index to which the array
should be extended.
void av_extend(AV* ar, I32 key)
av_fetch
Returns the SV at the specified index in the array. The "key"
is the index. If "lval" is set then the fetch will be part of
a store. Check that the return value is non-null before deref-
erencing it to a "SV*".
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on
tied arrays.
SV** av_fetch(AV* ar, I32 key, I32 lval)
av_fill Ensure than an array has a given number of elements, equivalent
to Perl’s "$#array = $fill;".
void av_fill(AV* ar, I32 fill)
av_len Returns the highest index in the array. Returns -1 if the
array is empty.
I32 av_len(AV* ar)
av_make Creates a new AV and populates it with a list of SVs. The SVs
are copied into the array, so they may be freed after the call
to av_make. The new AV will have a reference count of 1.
AV* av_make(I32 size, SV** svp)
av_pop Pops an SV off the end of the array. Returns &PL_sv_undef if
the array is empty.
SV* av_pop(AV* ar)
av_push Pushes an SV onto the end of the array. The array will grow
automatically to accommodate the addition.
void av_push(AV* ar, SV* val)
av_shift
Shifts an SV off the beginning of the array.
SV* av_shift(AV* ar)
av_store
Stores an SV in an array. The array index is specified as
"key". The return value will be NULL if the operation failed
or if the value did not need to be actually stored within the
array (as in the case of tied arrays). Otherwise it can be
dereferenced to get the original "SV*". Note that the caller
is responsible for suitably incrementing the reference count of
"val" before the call, and decrementing it if the function
returned NULL.
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on
tied arrays.
SV** av_store(AV* ar, I32 key, SV* val)
av_undef
Undefines the array. Frees the memory used by the array
itself.
void av_undef(AV* ar)
av_unshift
Unshift the given number of "undef" values onto the beginning
of the array. The array will grow automatically to accommodate
the addition. You must then use "av_store" to assign values to
these new elements.
void av_unshift(AV* ar, I32 num)
get_av Returns the AV of the specified Perl array. If "create" is set
and the Perl variable does not exist then it will be created.
If "create" is not set and the variable does not exist then
NULL is returned.
NOTE: the perl_ form of this function is deprecated.
AV* get_av(const char* name, I32 create)
newAV Creates a new AV. The reference count is set to 1.
AV* newAV()
sortsv Sort an array. Here is an example:
sortsv(AvARRAY(av), av_len(av)+1, Perl_sv_cmp_locale);
See lib/sort.pm for details about controlling the sorting algo-
rithm.
void sortsv(SV ** array, size_t num_elts, SVCOMPARE_t cmp)

Callback Functions

call_argv
Performs a callback to the specified Perl sub. See perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 call_argv(const char* sub_name, I32 flags, char** argv)
call_method
Performs a callback to the specified Perl method. The blessed
object must be on the stack. See perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 call_method(const char* methname, I32 flags)
call_pv Performs a callback to the specified Perl sub. See perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 call_pv(const char* sub_name, I32 flags)
call_sv Performs a callback to the Perl sub whose name is in the SV.
See perlcall.
NOTE: the perl_ form of this function is deprecated.
I32 call_sv(SV* sv, I32 flags)
ENTER Opening bracket on a callback. See "LEAVE" and perlcall.
ENTER;
eval_pv Tells Perl to "eval" the given string and return an SV* result.
NOTE: the perl_ form of this function is deprecated.
SV* eval_pv(const char* p, I32 croak_on_error)
eval_sv Tells Perl to "eval" the string in the SV.
NOTE: the perl_ form of this function is deprecated.
I32 eval_sv(SV* sv, I32 flags)
FREETMPS
Closing bracket for temporaries on a callback. See "SAVETMPS"
and perlcall.
FREETMPS;
LEAVE Closing bracket on a callback. See "ENTER" and perlcall.
LEAVE;
SAVETMPS
Opening bracket for temporaries on a callback. See "FREETMPS"
and perlcall.
SAVETMPS;

Cloning an interpreter

perl_clone
Create and return a new interpreter by cloning the current one.
perl_clone takes these flags as parameters:
CLONEf_COPY_STACKS - is used to, well, copy the stacks also,
without it we only clone the data and zero the stacks, with it
we copy the stacks and the new perl interpreter is ready to run
at the exact same point as the previous one. The pseudo-fork
code uses COPY_STACKS while the threads->new doesn’t.
CLONEf_KEEP_PTR_TABLE perl_clone keeps a ptr_table with the
pointer of the old variable as a key and the new variable as a
value, this allows it to check if something has been cloned and
not clone it again but rather just use the value and increase
the refcount. If KEEP_PTR_TABLE is not set then perl_clone will
kill the ptr_table using the function "ptr_ta-
ble_free(PL_ptr_table); PL_ptr_table = NULL;", reason to keep
it around is if you want to dup some of your own variable who
are outside the graph perl scans, example of this code is in
threads.xs create
CLONEf_CLONE_HOST This is a win32 thing, it is ignored on unix,
it tells perls win32host code (which is c++) to clone itself,
this is needed on win32 if you want to run two threads at the
same time, if you just want to do some stuff in a separate perl
interpreter and then throw it away and return to the original
one, you don’t need to do anything.
PerlInterpreter* perl_clone(PerlInterpreter* interp, UV flags)

CV Manipulation Functions

CvSTASH Returns the stash of the CV.
HV* CvSTASH(CV* cv)
get_cv Returns the CV of the specified Perl subroutine. If "create"
is set and the Perl subroutine does not exist then it will be
declared (which has the same effect as saying "sub name;"). If
"create" is not set and the subroutine does not exist then NULL
is returned.
NOTE: the perl_ form of this function is deprecated.
CV* get_cv(const char* name, I32 create)

Embedding Functions

cv_undef
Clear out all the active components of a CV. This can happen
either by an explicit "undef &foo", or by the reference count
going to zero. In the former case, we keep the CvOUTSIDE
pointer, so that any anonymous children can still follow the
full lexical scope chain.
void cv_undef(CV* cv)
load_module
Loads the module whose name is pointed to by the string part of
name. Note that the actual module name, not its filename,
should be given. Eg, "Foo::Bar" instead of "Foo/Bar.pm".
flags can be any of PERL_LOADMOD_DENY, PERL_LOADMOD_NOIMPORT,
or PERL_LOADMOD_IMPORT_OPS (or 0 for no flags). ver, if speci-
fied, provides version semantics similar to "use Foo::Bar VER-
SION". The optional trailing SV* arguments can be used to
specify arguments to the module’s import() method, similar to
"use Foo::Bar VERSION LIST".
void load_module(U32 flags, SV* name, SV* ver, ...)
nothreadhook
Stub that provides thread hook for perl_destruct when there are
no threads.
int nothreadhook()
perl_alloc
Allocates a new Perl interpreter. See perlembed.
PerlInterpreter* perl_alloc()
perl_construct
Initializes a new Perl interpreter. See perlembed.
void perl_construct(PerlInterpreter* interp)
perl_destruct
Shuts down a Perl interpreter. See perlembed.
int perl_destruct(PerlInterpreter* interp)
perl_free
Releases a Perl interpreter. See perlembed.
void perl_free(PerlInterpreter* interp)
perl_parse
Tells a Perl interpreter to parse a Perl script. See perlem-
bed.
int perl_parse(PerlInterpreter* interp, XSINIT_t xsinit, int argc, char** argv, char** env)
perl_run
Tells a Perl interpreter to run. See perlembed.
int perl_run(PerlInterpreter* interp)
require_pv
Tells Perl to "require" the file named by the string argument.
It is analogous to the Perl code "eval "require ’$file’"".
It’s even implemented that way; consider using load_module
instead.
NOTE: the perl_ form of this function is deprecated.
void require_pv(const char* pv)

Global Variables

PL_modglobal
"PL_modglobal" is a general purpose, interpreter global HV for
use by extensions that need to keep information on a per-inter-
preter basis. In a pinch, it can also be used as a symbol ta-
ble for extensions to share data among each other. It is a
good idea to use keys prefixed by the package name of the
extension that owns the data.
HV* PL_modglobal
PL_na A convenience variable which is typically used with "SvPV" when
one doesn’t care about the length of the string. It is usually
more efficient to either declare a local variable and use that
instead or to use the "SvPV_nolen" macro.
STRLEN PL_na
PL_sv_no
This is the "false" SV. See "PL_sv_yes". Always refer to this
as &PL_sv_no.
SV PL_sv_no
PL_sv_undef
This is the "undef" SV. Always refer to this as &PL_sv_undef.
SV PL_sv_undef
PL_sv_yes
This is the "true" SV. See "PL_sv_no". Always refer to this
as &PL_sv_yes.
SV PL_sv_yes

GV Functions

GvSV Return the SV from the GV.
SV* GvSV(GV* gv)
gv_fetchmeth
Returns the glob with the given "name" and a defined subroutine
or "NULL". The glob lives in the given "stash", or in the
stashes accessible via @ISA and UNIVERSAL::.
The argument "level" should be either 0 or -1. If "level==0",
as a side-effect creates a glob with the given "name" in the
given "stash" which in the case of success contains an alias
for the subroutine, and sets up caching info for this glob.
Similarly for all the searched stashes.
This function grants "SUPER" token as a postfix of the stash
name. The GV returned from "gv_fetchmeth" may be a method cache
entry, which is not visible to Perl code. So when calling
"call_sv", you should not use the GV directly; instead, you
should use the method’s CV, which can be obtained from the GV
with the "GvCV" macro.
GV* gv_fetchmeth(HV* stash, const char* name, STRLEN len, I32 level)
gv_fetchmethod
See gv_fetchmethod_autoload.
GV* gv_fetchmethod(HV* stash, const char* name)
gv_fetchmethod_autoload
Returns the glob which contains the subroutine to call to
invoke the method on the "stash". In fact in the presence of
autoloading this may be the glob for "AUTOLOAD". In this case
the corresponding variable $AUTOLOAD is already setup.
The third parameter of "gv_fetchmethod_autoload" determines
whether AUTOLOAD lookup is performed if the given method is not
present: non-zero means yes, look for AUTOLOAD; zero means no,
don’t look for AUTOLOAD. Calling "gv_fetchmethod" is equiva-
lent to calling "gv_fetchmethod_autoload" with a non-zero
"autoload" parameter.
These functions grant "SUPER" token as a prefix of the method
name. Note that if you want to keep the returned glob for a
long time, you need to check for it being "AUTOLOAD", since at
the later time the call may load a different subroutine due to
$AUTOLOAD changing its value. Use the glob created via a side
effect to do this.
These functions have the same side-effects and as "gv_fetch-
meth" with "level==0". "name" should be writable if contains
’:’ or "’ ’’". The warning against passing the GV returned by
"gv_fetchmeth" to "call_sv" apply equally to these functions.
GV* gv_fetchmethod_autoload(HV* stash, const char* name, I32 autoload)
gv_fetchmeth_autoload
Same as gv_fetchmeth(), but looks for autoloaded subroutines
too. Returns a glob for the subroutine.
For an autoloaded subroutine without a GV, will create a GV
even if "level < 0". For an autoloaded subroutine without a
stub, GvCV() of the result may be zero.
GV* gv_fetchmeth_autoload(HV* stash, const char* name, STRLEN len, I32 level)
gv_stashpv
Returns a pointer to the stash for a specified package. "name"
should be a valid UTF-8 string. If "create" is set then the
package will be created if it does not already exist. If "cre-
ate" is not set and the package does not exist then NULL is
returned.
HV* gv_stashpv(const char* name, I32 create)
gv_stashsv
Returns a pointer to the stash for a specified package, which
must be a valid UTF-8 string. See "gv_stashpv".
HV* gv_stashsv(SV* sv, I32 create)

Handy Values

Hash Manipulation Functions

get_hv Returns the HV of the specified Perl hash. If "create" is set
and the Perl variable does not exist then it will be created.
If "create" is not set and the variable does not exist then
NULL is returned.
NOTE: the perl_ form of this function is deprecated.
HV* get_hv(const char* name, I32 create)
HEf_SVKEY
This flag, used in the length slot of hash entries and magic
structures, specifies the structure contains an "SV*" pointer
where a "char*" pointer is to be expected. (For information
only--not to be used).
HeHASH Returns the computed hash stored in the hash entry.
U32 HeHASH(HE* he)
HeKEY Returns the actual pointer stored in the key slot of the hash
entry. The pointer may be either "char*" or "SV*", depending on
the value of "HeKLEN()". Can be assigned to. The "HePV()" or
"HeSVKEY()" macros are usually preferable for finding the value
of a key.
void* HeKEY(HE* he)
HeKLEN If this is negative, and amounts to "HEf_SVKEY", it indicates
the entry holds an "SV*" key. Otherwise, holds the actual
length of the key. Can be assigned to. The "HePV()" macro is
usually preferable for finding key lengths.
STRLEN HeKLEN(HE* he)
HePV Returns the key slot of the hash entry as a "char*" value,
doing any necessary dereferencing of possibly "SV*" keys. The
length of the string is placed in "len" (this is a macro, so do
not use &len). If you do not care about what the length of the
key is, you may use the global variable "PL_na", though this is
rather less efficient than using a local variable. Remember
though, that hash keys in perl are free to contain embedded
nulls, so using "strlen()" or similar is not a good way to find
the length of hash keys. This is very similar to the "SvPV()"
macro described elsewhere in this document.
char* HePV(HE* he, STRLEN len)
HeSVKEY Returns the key as an "SV*", or "Nullsv" if the hash entry does
not contain an "SV*" key.
SV* HeSVKEY(HE* he)
HeSVKEY_force
Returns the key as an "SV*". Will create and return a tempo-
rary mortal "SV*" if the hash entry contains only a "char*"
key.
SV* HeSVKEY_force(HE* he)
HeSVKEY_set
Sets the key to a given "SV*", taking care to set the appropri-
ate flags to indicate the presence of an "SV*" key, and returns
the same "SV*".
SV* HeSVKEY_set(HE* he, SV* sv)
HeVAL Returns the value slot (type "SV*") stored in the hash entry.
SV* HeVAL(HE* he)
HvNAME Returns the package name of a stash. See "SvSTASH", "CvSTASH".
char* HvNAME(HV* stash)
hv_clear
Clears a hash, making it empty.
void hv_clear(HV* tb)
hv_clear_placeholders
Clears any placeholders from a hash. If a restricted hash has
any of its keys marked as readonly and the key is subsequently
deleted, the key is not actually deleted but is marked by
assigning it a value of &PL_sv_placeholder. This tags it so it
will be ignored by future operations such as iterating over the
hash, but will still allow the hash to have a value reassigned
to the key at some future point. This function clears any such
placeholder keys from the hash. See Hash::Util::lock_keys()
for an example of its use.
void hv_clear_placeholders(HV* hb)
hv_delete
Deletes a key/value pair in the hash. The value SV is removed
from the hash and returned to the caller. The "klen" is the
length of the key. The "flags" value will normally be zero; if
set to G_DISCARD then NULL will be returned.
SV* hv_delete(HV* tb, const char* key, I32 klen, I32 flags)
hv_delete_ent
Deletes a key/value pair in the hash. The value SV is removed
from the hash and returned to the caller. The "flags" value
will normally be zero; if set to G_DISCARD then NULL will be
returned. "hash" can be a valid precomputed hash value, or 0
to ask for it to be computed.
SV* hv_delete_ent(HV* tb, SV* key, I32 flags, U32 hash)
hv_exists
Returns a boolean indicating whether the specified hash key
exists. The "klen" is the length of the key.
bool hv_exists(HV* tb, const char* key, I32 klen)
hv_exists_ent
Returns a boolean indicating whether the specified hash key
exists. "hash" can be a valid precomputed hash value, or 0 to
ask for it to be computed.
bool hv_exists_ent(HV* tb, SV* key, U32 hash)
hv_fetch
Returns the SV which corresponds to the specified key in the
hash. The "klen" is the length of the key. If "lval" is set
then the fetch will be part of a store. Check that the return
value is non-null before dereferencing it to an "SV*".
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on
tied hashes.
SV** hv_fetch(HV* tb, const char* key, I32 klen, I32 lval)
hv_fetch_ent
Returns the hash entry which corresponds to the specified key
in the hash. "hash" must be a valid precomputed hash number
for the given "key", or 0 if you want the function to compute
it. IF "lval" is set then the fetch will be part of a store.
Make sure the return value is non-null before accessing it.
The return value when "tb" is a tied hash is a pointer to a
static location, so be sure to make a copy of the structure if
you need to store it somewhere.
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on
tied hashes.
HE* hv_fetch_ent(HV* tb, SV* key, I32 lval, U32 hash)
hv_iterinit
Prepares a starting point to traverse a hash table. Returns
the number of keys in the hash (i.e. the same as "HvKEYS(tb)").
The return value is currently only meaningful for hashes with-
out tie magic.
NOTE: Before version 5.004_65, "hv_iterinit" used to return the
number of hash buckets that happen to be in use. If you still
need that esoteric value, you can get it through the macro
"HvFILL(tb)".
I32 hv_iterinit(HV* tb)
hv_iterkey
Returns the key from the current position of the hash iterator.
See "hv_iterinit".
char* hv_iterkey(HE* entry, I32* retlen)
hv_iterkeysv
Returns the key as an "SV*" from the current position of the
hash iterator. The return value will always be a mortal copy
of the key. Also see "hv_iterinit".
SV* hv_iterkeysv(HE* entry)
hv_iternext
Returns entries from a hash iterator. See "hv_iterinit".
You may call "hv_delete" or "hv_delete_ent" on the hash entry
that the iterator currently points to, without losing your
place or invalidating your iterator. Note that in this case
the current entry is deleted from the hash with your iterator
holding the last reference to it. Your iterator is flagged to
free the entry on the next call to "hv_iternext", so you must
not discard your iterator immediately else the entry will leak
- call "hv_iternext" to trigger the resource deallocation.
HE* hv_iternext(HV* tb)
hv_iternextsv
Performs an "hv_iternext", "hv_iterkey", and "hv_iterval" in
one operation.
SV* hv_iternextsv(HV* hv, char** key, I32* retlen)
hv_iternext_flags
Returns entries from a hash iterator. See "hv_iterinit" and
"hv_iternext". The "flags" value will normally be zero; if
HV_ITERNEXT_WANTPLACEHOLDERS is set the placeholders keys (for
restricted hashes) will be returned in addition to normal keys.
By default placeholders are automatically skipped over. Cur-
rently a placeholder is implemented with a value that is
&Perl_sv_placeholder. Note that the implementation of place-
holders and restricted hashes may change, and the implementa-
tion currently is insufficiently abstracted for any change to
be tidy.
NOTE: this function is experimental and may change or be
removed without notice.
HE* hv_iternext_flags(HV* tb, I32 flags)
hv_iterval
Returns the value from the current position of the hash itera-
tor. See "hv_iterkey".
SV* hv_iterval(HV* tb, HE* entry)
hv_magic
Adds magic to a hash. See "sv_magic".
void hv_magic(HV* hv, GV* gv, int how)
hv_scalar
Evaluates the hash in scalar context and returns the result.
Handles magic when the hash is tied.
SV* hv_scalar(HV* hv)
hv_store
Stores an SV in a hash. The hash key is specified as "key" and
"klen" is the length of the key. The "hash" parameter is the
precomputed hash value; if it is zero then Perl will compute
it. The return value will be NULL if the operation failed or
if the value did not need to be actually stored within the hash
(as in the case of tied hashes). Otherwise it can be derefer-
enced to get the original "SV*". Note that the caller is
responsible for suitably incrementing the reference count of
"val" before the call, and decrementing it if the function
returned NULL. Effectively a successful hv_store takes owner-
ship of one reference to "val". This is usually what you want;
a newly created SV has a reference count of one, so if all your
code does is create SVs then store them in a hash, hv_store
will own the only reference to the new SV, and your code
doesn’t need to do anything further to tidy up. hv_store is
not implemented as a call to hv_store_ent, and does not create
a temporary SV for the key, so if your key data is not already
in SV form then use hv_store in preference to hv_store_ent.
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on
tied hashes.
SV** hv_store(HV* tb, const char* key, I32 klen, SV* val, U32 hash)
hv_store_ent
Stores "val" in a hash. The hash key is specified as "key".
The "hash" parameter is the precomputed hash value; if it is
zero then Perl will compute it. The return value is the new
hash entry so created. It will be NULL if the operation failed
or if the value did not need to be actually stored within the
hash (as in the case of tied hashes). Otherwise the contents
of the return value can be accessed using the "He?" macros
described here. Note that the caller is responsible for
suitably incrementing the reference count of "val" before the
call, and decrementing it if the function returned NULL.
Effectively a successful hv_store_ent takes ownership of one
reference to "val". This is usually what you want; a newly
created SV has a reference count of one, so if all your code
does is create SVs then store them in a hash, hv_store will own
the only reference to the new SV, and your code doesn’t need to
do anything further to tidy up. Note that hv_store_ent only
reads the "key"; unlike "val" it does not take ownership of it,
so maintaining the correct reference count on "key" is entirely
the caller’s responsibility. hv_store is not implemented as a
call to hv_store_ent, and does not create a temporary SV for
the key, so if your key data is not already in SV form then use
hv_store in preference to hv_store_ent.
See "Understanding the Magic of Tied Hashes and Arrays" in
perlguts for more information on how to use this function on
tied hashes.
HE* hv_store_ent(HV* tb, SV* key, SV* val, U32 hash)
hv_undef
Undefines the hash.
void hv_undef(HV* tb)
newHV Creates a new HV. The reference count is set to 1.
HV* newHV()

Magical Functions

mg_clear
Clear something magical that the SV represents. See
"sv_magic".
int mg_clear(SV* sv)
mg_copy Copies the magic from one SV to another. See "sv_magic".
int mg_copy(SV* sv, SV* nsv, const char* key, I32 klen)
mg_find Finds the magic pointer for type matching the SV. See
"sv_magic".
MAGIC* mg_find(SV* sv, int type)
mg_free Free any magic storage used by the SV. See "sv_magic".
int mg_free(SV* sv)
mg_get Do magic after a value is retrieved from the SV. See
"sv_magic".
int mg_get(SV* sv)
mg_length
Report on the SV’s length. See "sv_magic".
U32 mg_length(SV* sv)
mg_magical
Turns on the magical status of an SV. See "sv_magic".
void mg_magical(SV* sv)
mg_set Do magic after a value is assigned to the SV. See "sv_magic".
int mg_set(SV* sv)
SvGETMAGIC
Invokes "mg_get" on an SV if it has ’get’ magic. This macro
evaluates its argument more than once.
void SvGETMAGIC(SV* sv)
SvLOCK Arranges for a mutual exclusion lock to be obtained on sv if a
suitable module has been loaded.
void SvLOCK(SV* sv)
SvSETMAGIC
Invokes "mg_set" on an SV if it has ’set’ magic. This macro
evaluates its argument more than once.
void SvSETMAGIC(SV* sv)
SvSetMagicSV
Like "SvSetSV", but does any set magic required afterwards.
void SvSetMagicSV(SV* dsb, SV* ssv)
SvSetMagicSV_nosteal
Like "SvSetSV_nosteal", but does any set magic required after-
wards.
void SvSetMagicSV_nosteal(SV* dsv, SV* ssv)
SvSetSV Calls "sv_setsv" if dsv is not the same as ssv. May evaluate
arguments more than once.
void SvSetSV(SV* dsb, SV* ssv)
SvSetSV_nosteal
Calls a non-destructive version of "sv_setsv" if dsv is not the
same as ssv. May evaluate arguments more than once.
void SvSetSV_nosteal(SV* dsv, SV* ssv)
SvSHARE Arranges for sv to be shared between threads if a suitable mod-
ule has been loaded.
void SvSHARE(SV* sv)
SvUNLOCK
Releases a mutual exclusion lock on sv if a suitable module has
been loaded.
void SvUNLOCK(SV* sv)

Memory Management

Copy The XSUB-writer’s interface to the C "memcpy" function. The
"src" is the source, "dest" is the destination, "nitems" is the
number of items, and "type" is the type. May fail on overlap-
ping copies. See also "Move".
void Copy(void* src, void* dest, int nitems, type)
CopyD Like "Copy" but returns dest. Useful for encouraging compilers
to tail-call optimise.
void * CopyD(void* src, void* dest, int nitems, type)
Move The XSUB-writer’s interface to the C "memmove" function. The
"src" is the source, "dest" is the destination, "nitems" is the
number of items, and "type" is the type. Can do overlapping
moves. See also "Copy".
void Move(void* src, void* dest, int nitems, type)
MoveD Like "Move" but returns dest. Useful for encouraging compilers
to tail-call optimise.
void * MoveD(void* src, void* dest, int nitems, type)
New The XSUB-writer’s interface to the C "malloc" function.
void New(int id, void* ptr, int nitems, type)
Newc The XSUB-writer’s interface to the C "malloc" function, with
cast.
void Newc(int id, void* ptr, int nitems, type, cast)
Newz The XSUB-writer’s interface to the C "malloc" function. The
allocated memory is zeroed with "memzero".
void Newz(int id, void* ptr, int nitems, type)
Poison Fill up memory with a pattern (byte 0xAB over and over again)
that hopefully catches attempts to access uninitialized memory.
void Poison(void* dest, int nitems, type)
Renew The XSUB-writer’s interface to the C "realloc" function.
void Renew(void* ptr, int nitems, type)
Renewc The XSUB-writer’s interface to the C "realloc" function, with
cast.
void Renewc(void* ptr, int nitems, type, cast)
Safefree
The XSUB-writer’s interface to the C "free" function.
void Safefree(void* ptr)
savepv Perl’s version of "strdup()". Returns a pointer to a newly
allocated string which is a duplicate of "pv". The size of the
string is determined by "strlen()". The memory allocated for
the new string can be freed with the "Safefree()" function.
char* savepv(const char* pv)
savepvn Perl’s version of what "strndup()" would be if it existed.
Returns a pointer to a newly allocated string which is a dupli-
cate of the first "len" bytes from "pv". The memory allocated
for the new string can be freed with the "Safefree()" function.
char* savepvn(const char* pv, I32 len)
savesharedpv
A version of "savepv()" which allocates the duplicate string in
memory which is shared between threads.
char* savesharedpv(const char* pv)
StructCopy
This is an architecture-independent macro to copy one structure
to another.
void StructCopy(type src, type dest, type)
Zero The XSUB-writer’s interface to the C "memzero" function. The
"dest" is the destination, "nitems" is the number of items, and
"type" is the type.
void Zero(void* dest, int nitems, type)
ZeroD Like "Zero" but returns dest. Useful for encouraging compilers
to tail-call optimise.
void * ZeroD(void* dest, int nitems, type)

Miscellaneous Functions

fbm_compile
Analyses the string in order to make fast searches on it using
fbm_instr() -- the Boyer-Moore algorithm.
void fbm_compile(SV* sv, U32 flags)
fbm_instr
Returns the location of the SV in the string delimited by "str"
and "strend". It returns "Nullch" if the string can’t be
found. The "sv" does not have to be fbm_compiled, but the
search will not be as fast then.
char* fbm_instr(unsigned char* big, unsigned char* bigend, SV* littlesv, U32 flags)
form Takes a sprintf-style format pattern and conventional (non-SV)
arguments and returns the formatted string.
(char *) Perl_form(pTHX_ const char* pat, ...)
can be used any place a string (char *) is required:
char * s = Perl_form("%d.%d",major,minor);
Uses a single private buffer so if you want to format several
strings you must explicitly copy the earlier strings away (and
free the copies when you are done).
char* form(const char* pat, ...)
getcwd_sv
Fill the sv with current working directory
int getcwd_sv(SV* sv)
strEQ Test two strings to see if they are equal. Returns true or
false.
bool strEQ(char* s1, char* s2)
strGE Test two strings to see if the first, "s1", is greater than or
equal to the second, "s2". Returns true or false.
bool strGE(char* s1, char* s2)
strGT Test two strings to see if the first, "s1", is greater than the
second, "s2". Returns true or false.
bool strGT(char* s1, char* s2)
strLE Test two strings to see if the first, "s1", is less than or
equal to the second, "s2". Returns true or false.
bool strLE(char* s1, char* s2)
strLT Test two strings to see if the first, "s1", is less than the
second, "s2". Returns true or false.
bool strLT(char* s1, char* s2)
strNE Test two strings to see if they are different. Returns true or
false.
bool strNE(char* s1, char* s2)
strnEQ Test two strings to see if they are equal. The "len" parameter
indicates the number of bytes to compare. Returns true or
false. (A wrapper for "strncmp").
bool strnEQ(char* s1, char* s2, STRLEN len)
strnNE Test two strings to see if they are different. The "len"
parameter indicates the number of bytes to compare. Returns
true or false. (A wrapper for "strncmp").
bool strnNE(char* s1, char* s2, STRLEN len)
sv_nolocking
Dummy routine which "locks" an SV when there is no locking mod-
ule present. Exists to avoid test for a NULL function pointer
and because it could potentially warn under some level of
strict-ness.
void sv_nolocking(SV *)
sv_nosharing
Dummy routine which "shares" an SV when there is no sharing
module present. Exists to avoid test for a NULL function
pointer and because it could potentially warn under some level
of strict-ness.
void sv_nosharing(SV *)
sv_nounlocking
Dummy routine which "unlocks" an SV when there is no locking
module present. Exists to avoid test for a NULL function
pointer and because it could potentially warn under some level
of strict-ness.
void sv_nounlocking(SV *)

Numeric functions

grok_bin
converts a string representing a binary number to numeric form.
On entry start and *len give the string to scan, *flags gives
conversion flags, and result should be NULL or a pointer to an
NV. The scan stops at the end of the string, or the first
invalid character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set
in *flags, encountering an invalid character will also trigger
a warning. On return *len is set to the length of the scanned
string, and *flags gives output flags.
If the value is <= UV_MAX it is returned as a UV, the output
flags are clear, and nothing is written to *result. If the
value is > UV_MAX "grok_bin" returns UV_MAX, sets
"PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes
the value to *result (or the value is discarded if result is
NULL).
The binary number may optionally be prefixed with "0b" or "b"
unless "PERL_SCAN_DISALLOW_PREFIX" is set in *flags on entry.
If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then the
binary number may use ’_’ characters to separate digits.
UV grok_bin(char* start, STRLEN* len, I32* flags, NV *result)
grok_hex
converts a string representing a hex number to numeric form.
On entry start and *len give the string to scan, *flags gives
conversion flags, and result should be NULL or a pointer to an
NV. The scan stops at the end of the string, or the first
invalid character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set
in *flags, encountering an invalid character will also trigger
a warning. On return *len is set to the length of the scanned
string, and *flags gives output flags.
If the value is <= UV_MAX it is returned as a UV, the output
flags are clear, and nothing is written to *result. If the
value is > UV_MAX "grok_hex" returns UV_MAX, sets
"PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes
the value to *result (or the value is discarded if result is
NULL).
The hex number may optionally be prefixed with "0x" or "x"
unless "PERL_SCAN_DISALLOW_PREFIX" is set in *flags on entry.
If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then the hex
number may use ’_’ characters to separate digits.
UV grok_hex(char* start, STRLEN* len, I32* flags, NV *result)
grok_number
Recognise (or not) a number. The type of the number is
returned (0 if unrecognised), otherwise it is a bit-ORed combi-
nation of IS_NUMBER_IN_UV, IS_NUMBER_GREATER_THAN_UV_MAX,
IS_NUMBER_NOT_INT, IS_NUMBER_NEG, IS_NUMBER_INFINITY, IS_NUM-
BER_NAN (defined in perl.h).
If the value of the number can fit an in UV, it is returned in
the *valuep IS_NUMBER_IN_UV will be set to indicate that *val-
uep is valid, IS_NUMBER_IN_UV will never be set unless *valuep
is valid, but *valuep may have been assigned to during process-
ing even though IS_NUMBER_IN_UV is not set on return. If val-
uep is NULL, IS_NUMBER_IN_UV will be set for the same cases as
when valuep is non-NULL, but no actual assignment (or SEGV)
will occur.
IS_NUMBER_NOT_INT will be set with IS_NUMBER_IN_UV if trailing
decimals were seen (in which case *valuep gives the true value
truncated to an integer), and IS_NUMBER_NEG if the number is
negative (in which case *valuep holds the absolute value).
IS_NUMBER_IN_UV is not set if e notation was used or the number
is larger than a UV.
int grok_number(const char *pv, STRLEN len, UV *valuep)
grok_numeric_radix
Scan and skip for a numeric decimal separator (radix).
bool grok_numeric_radix(const char **sp, const char *send)
grok_oct
converts a string representing an octal number to numeric form.
On entry start and *len give the string to scan, *flags gives
conversion flags, and result should be NULL or a pointer to an
NV. The scan stops at the end of the string, or the first
invalid character. Unless "PERL_SCAN_SILENT_ILLDIGIT" is set
in *flags, encountering an invalid character will also trigger
a warning. On return *len is set to the length of the scanned
string, and *flags gives output flags.
If the value is <= UV_MAX it is returned as a UV, the output
flags are clear, and nothing is written to *result. If the
value is > UV_MAX "grok_oct" returns UV_MAX, sets
"PERL_SCAN_GREATER_THAN_UV_MAX" in the output flags, and writes
the value to *result (or the value is discarded if result is
NULL).
If "PERL_SCAN_ALLOW_UNDERSCORES" is set in *flags then the
octal number may use ’_’ characters to separate digits.
UV grok_oct(char* start, STRLEN* len, I32* flags, NV *result)
scan_bin
For backwards compatibility. Use "grok_bin" instead.
NV scan_bin(char* start, STRLEN len, STRLEN* retlen)
scan_hex
For backwards compatibility. Use "grok_hex" instead.
NV scan_hex(char* start, STRLEN len, STRLEN* retlen)
scan_oct
For backwards compatibility. Use "grok_oct" instead.
NV scan_oct(char* start, STRLEN len, STRLEN* retlen)

Optree Manipulation Functions

cv_const_sv
If "cv" is a constant sub eligible for inlining. returns the
constant value returned by the sub. Otherwise, returns NULL.
Constant subs can be created with "newCONSTSUB" or as described
in "Constant Functions" in perlsub.
SV* cv_const_sv(CV* cv)
newCONSTSUB
Creates a constant sub equivalent to Perl "sub FOO () { 123 }"
which is eligible for inlining at compile-time.
CV* newCONSTSUB(HV* stash, char* name, SV* sv)
newXS Used by "xsubpp" to hook up XSUBs as Perl subs.

Pad Data Structures

pad_sv Get the value at offset po in the current pad. Use macro
PAD_SV instead of calling this function directly.
SV* pad_sv(PADOFFSET po)

Stack Manipulation Macros

dMARK Declare a stack marker variable, "mark", for the XSUB. See
"MARK" and "dORIGMARK".
dMARK;
dORIGMARK
Saves the original stack mark for the XSUB. See "ORIGMARK".
dORIGMARK;
dSP Declares a local copy of perl’s stack pointer for the XSUB,
available via the "SP" macro. See "SP".
dSP;
EXTEND Used to extend the argument stack for an XSUB’s return values.
Once used, guarantees that there is room for at least "nitems"
to be pushed onto the stack.
void EXTEND(SP, int nitems)
MARK Stack marker variable for the XSUB. See "dMARK".
mPUSHi Push an integer onto the stack. The stack must have room for
this element. Handles ’set’ magic. Does not use "TARG". See
also "PUSHi", "mXPUSHi" and "XPUSHi".
void mPUSHi(IV iv)
mPUSHn Push a double onto the stack. The stack must have room for
this element. Handles ’set’ magic. Does not use "TARG". See
also "PUSHn", "mXPUSHn" and "XPUSHn".
void mPUSHn(NV nv)
mPUSHp Push a string onto the stack. The stack must have room for
this element. The "len" indicates the length of the string.
Handles ’set’ magic. Does not use "TARG". See also "PUSHp",
"mXPUSHp" and "XPUSHp".
void mPUSHp(char* str, STRLEN len)
mPUSHu Push an unsigned integer onto the stack. The stack must have
room for this element. Handles ’set’ magic. Does not use
"TARG". See also "PUSHu", "mXPUSHu" and "XPUSHu".
void mPUSHu(UV uv)
mXPUSHi Push an integer onto the stack, extending the stack if neces-
sary. Handles ’set’ magic. Does not use "TARG". See also
"XPUSHi", "mPUSHi" and "PUSHi".
void mXPUSHi(IV iv)
mXPUSHn Push a double onto the stack, extending the stack if necessary.
Handles ’set’ magic. Does not use "TARG". See also "XPUSHn",
"mPUSHn" and "PUSHn".
void mXPUSHn(NV nv)
mXPUSHp Push a string onto the stack, extending the stack if necessary.
The "len" indicates the length of the string. Handles ’set’
magic. Does not use "TARG". See also "XPUSHp", "mPUSHp" and
"PUSHp".
void mXPUSHp(char* str, STRLEN len)
mXPUSHu Push an unsigned integer onto the stack, extending the stack if
necessary. Handles ’set’ magic. Does not use "TARG". See
also "XPUSHu", "mPUSHu" and "PUSHu".
void mXPUSHu(UV uv)
ORIGMARK
The original stack mark for the XSUB. See "dORIGMARK".
POPi Pops an integer off the stack.
IV POPi
POPl Pops a long off the stack.
long POPl
POPn Pops a double off the stack.
NV POPn
POPp Pops a string off the stack. Deprecated. New code should pro-
vide a STRLEN n_a and use POPpx.
char* POPp
POPpbytex
Pops a string off the stack which must consist of bytes i.e.
characters < 256. Requires a variable STRLEN n_a in scope.
char* POPpbytex
POPpx Pops a string off the stack. Requires a variable STRLEN n_a in
scope.
char* POPpx
POPs Pops an SV off the stack.
SV* POPs
PUSHi Push an integer onto the stack. The stack must have room for
this element. Handles ’set’ magic. Uses "TARG", so "dTARGET"
or "dXSTARG" should be called to declare it. Do not call mul-
tiple "TARG"-oriented macros to return lists from XSUB’s - see
"mPUSHi" instead. See also "XPUSHi" and "mXPUSHi".
void PUSHi(IV iv)
PUSHMARK
Opening bracket for arguments on a callback. See "PUTBACK" and
perlcall.
void PUSHMARK(SP)
PUSHmortal
Push a new mortal SV onto the stack. The stack must have room
for this element. Does not handle ’set’ magic. Does not use
"TARG". See also "PUSHs", "XPUSHmortal" and "XPUSHs".
void PUSHmortal()
PUSHn Push a double onto the stack. The stack must have room for
this element. Handles ’set’ magic. Uses "TARG", so "dTARGET"
or "dXSTARG" should be called to declare it. Do not call mul-
tiple "TARG"-oriented macros to return lists from XSUB’s - see
"mPUSHn" instead. See also "XPUSHn" and "mXPUSHn".
void PUSHn(NV nv)
PUSHp Push a string onto the stack. The stack must have room for
this element. The "len" indicates the length of the string.
Handles ’set’ magic. Uses "TARG", so "dTARGET" or "dXSTARG"
should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB’s - see
"mPUSHp" instead. See also "XPUSHp" and "mXPUSHp".
void PUSHp(char* str, STRLEN len)
PUSHs Push an SV onto the stack. The stack must have room for this
element. Does not handle ’set’ magic. Does not use "TARG".
See also "PUSHmortal", "XPUSHs" and "XPUSHmortal".
void PUSHs(SV* sv)
PUSHu Push an unsigned integer onto the stack. The stack must have
room for this element. Handles ’set’ magic. Uses "TARG", so
"dTARGET" or "dXSTARG" should be called to declare it. Do not
call multiple "TARG"-oriented macros to return lists from
XSUB’s - see "mPUSHu" instead. See also "XPUSHu" and
"mXPUSHu".
void PUSHu(UV uv)
PUTBACK Closing bracket for XSUB arguments. This is usually handled by
"xsubpp". See "PUSHMARK" and perlcall for other uses.
PUTBACK;
SP Stack pointer. This is usually handled by "xsubpp". See "dSP"
and "SPAGAIN".
SPAGAIN Refetch the stack pointer. Used after a callback. See perl-
call.
SPAGAIN;
XPUSHi Push an integer onto the stack, extending the stack if neces-
sary. Handles ’set’ magic. Uses "TARG", so "dTARGET" or "dXS-
TARG" should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB’s - see
"mXPUSHi" instead. See also "PUSHi" and "mPUSHi".
void XPUSHi(IV iv)
XPUSHmortal
Push a new mortal SV onto the stack, extending the stack if
necessary. Does not handle ’set’ magic. Does not use "TARG".
See also "XPUSHs", "PUSHmortal" and "PUSHs".
void XPUSHmortal()
XPUSHn Push a double onto the stack, extending the stack if necessary.
Handles ’set’ magic. Uses "TARG", so "dTARGET" or "dXSTARG"
should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB’s - see
"mXPUSHn" instead. See also "PUSHn" and "mPUSHn".
void XPUSHn(NV nv)
XPUSHp Push a string onto the stack, extending the stack if necessary.
The "len" indicates the length of the string. Handles ’set’
magic. Uses "TARG", so "dTARGET" or "dXSTARG" should be called
to declare it. Do not call multiple "TARG"-oriented macros to
return lists from XSUB’s - see "mXPUSHp" instead. See also
"PUSHp" and "mPUSHp".
void XPUSHp(char* str, STRLEN len)
XPUSHs Push an SV onto the stack, extending the stack if necessary.
Does not handle ’set’ magic. Does not use "TARG". See also
"XPUSHmortal", "PUSHs" and "PUSHmortal".
void XPUSHs(SV* sv)
XPUSHu Push an unsigned integer onto the stack, extending the stack if
necessary. Handles ’set’ magic. Uses "TARG", so "dTARGET" or
"dXSTARG" should be called to declare it. Do not call multiple
"TARG"-oriented macros to return lists from XSUB’s - see
"mXPUSHu" instead. See also "PUSHu" and "mPUSHu".
void XPUSHu(UV uv)
XSRETURN
Return from XSUB, indicating number of items on the stack.
This is usually handled by "xsubpp".
void XSRETURN(int nitems)
XSRETURN_EMPTY
Return an empty list from an XSUB immediately.
XSRETURN_EMPTY;
XSRETURN_IV
Return an integer from an XSUB immediately. Uses "XST_mIV".
void XSRETURN_IV(IV iv)
XSRETURN_NO
Return &PL_sv_no from an XSUB immediately. Uses "XST_mNO".
XSRETURN_NO;
XSRETURN_NV
Return a double from an XSUB immediately. Uses "XST_mNV".
void XSRETURN_NV(NV nv)
XSRETURN_PV
Return a copy of a string from an XSUB immediately. Uses
"XST_mPV".
void XSRETURN_PV(char* str)
XSRETURN_UNDEF
Return &PL_sv_undef from an XSUB immediately. Uses
"XST_mUNDEF".
XSRETURN_UNDEF;
XSRETURN_UV
Return an integer from an XSUB immediately. Uses "XST_mUV".
void XSRETURN_UV(IV uv)
XSRETURN_YES
Return &PL_sv_yes from an XSUB immediately. Uses "XST_mYES".
XSRETURN_YES;
XST_mIV Place an integer into the specified position "pos" on the
stack. The value is stored in a new mortal SV.
void XST_mIV(int pos, IV iv)
XST_mNO Place &PL_sv_no into the specified position "pos" on the stack.
void XST_mNO(int pos)
XST_mNV Place a double into the specified position "pos" on the stack.
The value is stored in a new mortal SV.
void XST_mNV(int pos, NV nv)
XST_mPV Place a copy of a string into the specified position "pos" on
the stack. The value is stored in a new mortal SV.
void XST_mPV(int pos, char* str)
XST_mUNDEF
Place &PL_sv_undef into the specified position "pos" on the
stack.
void XST_mUNDEF(int pos)
XST_mYES
Place &PL_sv_yes into the specified position "pos" on the
stack.
void XST_mYES(int pos)

SV Flags

svtype An enum of flags for Perl types. These are found in the file
sv.h in the "svtype" enum. Test these flags with the "SvTYPE"
macro.
SVt_IV Integer type flag for scalars. See "svtype".
SVt_NV Double type flag for scalars. See "svtype".
SVt_PV Pointer type flag for scalars. See "svtype".
SVt_PVAV
Type flag for arrays. See "svtype".
SVt_PVCV
Type flag for code refs. See "svtype".
SVt_PVHV
Type flag for hashes. See "svtype".
SVt_PVMG
Type flag for blessed scalars. See "svtype".

SV Manipulation Functions

get_sv Returns the SV of the specified Perl scalar. If "create" is
set and the Perl variable does not exist then it will be cre-
ated. If "create" is not set and the variable does not exist
then NULL is returned.
NOTE: the perl_ form of this function is deprecated.
SV* get_sv(const char* name, I32 create)
looks_like_number
Test if the content of an SV looks like a number (or is a num-
ber). "Inf" and "Infinity" are treated as numbers (so will not
issue a non-numeric warning), even if your atof() doesn’t grok
them.
I32 looks_like_number(SV* sv)
newRV_inc
Creates an RV wrapper for an SV. The reference count for the
original SV is incremented.
SV* newRV_inc(SV* sv)
newRV_noinc
Creates an RV wrapper for an SV. The reference count for the
original SV is not incremented.
SV* newRV_noinc(SV *sv)
NEWSV Creates a new SV. A non-zero "len" parameter indicates the
number of bytes of preallocated string space the SV should
have. An extra byte for a tailing NUL is also reserved.
(SvPOK is not set for the SV even if string space is allo-
cated.) The reference count for the new SV is set to 1. "id"
is an integer id between 0 and 1299 (used to identify leaks).
SV* NEWSV(int id, STRLEN len)
newSV Create a new null SV, or if len > 0, create a new empty SVt_PV
type SV with an initial PV allocation of len+1. Normally
accessed via the "NEWSV" macro.
SV* newSV(STRLEN len)
newSViv Creates a new SV and copies an integer into it. The reference
count for the SV is set to 1.
SV* newSViv(IV i)
newSVnv Creates a new SV and copies a floating point value into it.
The reference count for the SV is set to 1.
SV* newSVnv(NV n)
newSVpv Creates a new SV and copies a string into it. The reference
count for the SV is set to 1. If "len" is zero, Perl will com-
pute the length using strlen(). For efficiency, consider using
"newSVpvn" instead.
SV* newSVpv(const char* s, STRLEN len)
newSVpvf
Creates a new SV and initializes it with the string formatted
like "sprintf".
SV* newSVpvf(const char* pat, ...)
newSVpvn
Creates a new SV and copies a string into it. The reference
count for the SV is set to 1. Note that if "len" is zero, Perl
will create a zero length string. You are responsible for
ensuring that the source string is at least "len" bytes long.
If the "s" argument is NULL the new SV will be undefined.
SV* newSVpvn(const char* s, STRLEN len)
newSVpvn_share
Creates a new SV with its SvPVX pointing to a shared string in
the string table. If the string does not already exist in the
table, it is created first. Turns on READONLY and FAKE. The
string’s hash is stored in the UV slot of the SV; if the "hash"
parameter is non-zero, that value is used; otherwise the hash
is computed. The idea here is that as the string table is used
for shared hash keys these strings will have SvPVX == HeKEY and
hash lookup will avoid string compare.
SV* newSVpvn_share(const char* s, I32 len, U32 hash)
newSVrv Creates a new SV for the RV, "rv", to point to. If "rv" is not
an RV then it will be upgraded to one. If "classname" is non-
null then the new SV will be blessed in the specified package.
The new SV is returned and its reference count is 1.
SV* newSVrv(SV* rv, const char* classname)
newSVsv Creates a new SV which is an exact duplicate of the original
SV. (Uses "sv_setsv").
SV* newSVsv(SV* old)
newSVuv Creates a new SV and copies an unsigned integer into it. The
reference count for the SV is set to 1.
SV* newSVuv(UV u)
SvCUR Returns the length of the string which is in the SV. See
"SvLEN".
STRLEN SvCUR(SV* sv)
SvCUR_set
Set the length of the string which is in the SV. See "SvCUR".
void SvCUR_set(SV* sv, STRLEN len)
SvEND Returns a pointer to the last character in the string which is
in the SV. See "SvCUR". Access the character as *(SvEND(sv)).
char* SvEND(SV* sv)
SvGROW Expands the character buffer in the SV so that it has room for
the indicated number of bytes (remember to reserve space for an
extra trailing NUL character). Calls "sv_grow" to perform the
expansion if necessary. Returns a pointer to the character
buffer.
char * SvGROW(SV* sv, STRLEN len)
SvIOK Returns a boolean indicating whether the SV contains an inte-
ger.
bool SvIOK(SV* sv)
SvIOKp Returns a boolean indicating whether the SV contains an inte-
ger. Checks the private setting. Use "SvIOK".
bool SvIOKp(SV* sv)
SvIOK_notUV
Returns a boolean indicating whether the SV contains a signed
integer.
bool SvIOK_notUV(SV* sv)
SvIOK_off
Unsets the IV status of an SV.
void SvIOK_off(SV* sv)
SvIOK_on
Tells an SV that it is an integer.
void SvIOK_on(SV* sv)
SvIOK_only
Tells an SV that it is an integer and disables all other OK
bits.
void SvIOK_only(SV* sv)
SvIOK_only_UV
Tells and SV that it is an unsigned integer and disables all
other OK bits.
void SvIOK_only_UV(SV* sv)
SvIOK_UV
Returns a boolean indicating whether the SV contains an
unsigned integer.
bool SvIOK_UV(SV* sv)
SvIsCOW Returns a boolean indicating whether the SV is Copy-On-Write.
(either shared hash key scalars, or full Copy On Write scalars
if 5.9.0 is configured for COW)
bool SvIsCOW(SV* sv)
SvIsCOW_shared_hash
Returns a boolean indicating whether the SV is Copy-On-Write
shared hash key scalar.
bool SvIsCOW_shared_hash(SV* sv)
SvIV Coerces the given SV to an integer and returns it. See "SvIVx"
for a version which guarantees to evaluate sv only once.
IV SvIV(SV* sv)
SvIVx Coerces the given SV to an integer and returns it. Guarantees
to evaluate sv only once. Use the more efficient "SvIV" other-
wise.
IV SvIVx(SV* sv)
SvIVX Returns the raw value in the SV’s IV slot, without checks or
conversions. Only use when you are sure SvIOK is true. See
also "SvIV()".
IV SvIVX(SV* sv)
SvLEN Returns the size of the string buffer in the SV, not including
any part attributable to "SvOOK". See "SvCUR".
STRLEN SvLEN(SV* sv)
SvNIOK Returns a boolean indicating whether the SV contains a number,
integer or double.
bool SvNIOK(SV* sv)
SvNIOKp Returns a boolean indicating whether the SV contains a number,
integer or double. Checks the private setting. Use "SvNIOK".
bool SvNIOKp(SV* sv)
SvNIOK_off
Unsets the NV/IV status of an SV.
void SvNIOK_off(SV* sv)
SvNOK Returns a boolean indicating whether the SV contains a double.
bool SvNOK(SV* sv)
SvNOKp Returns a boolean indicating whether the SV contains a double.
Checks the private setting. Use "SvNOK".
bool SvNOKp(SV* sv)
SvNOK_off
Unsets the NV status of an SV.
void SvNOK_off(SV* sv)
SvNOK_on
Tells an SV that it is a double.
void SvNOK_on(SV* sv)
SvNOK_only
Tells an SV that it is a double and disables all other OK bits.
void SvNOK_only(SV* sv)
SvNV Coerce the given SV to a double and return it. See "SvNVx" for
a version which guarantees to evaluate sv only once.
NV SvNV(SV* sv)
SvNVx Coerces the given SV to a double and returns it. Guarantees to
evaluate sv only once. Use the more efficient "SvNV" otherwise.
NV SvNVx(SV* sv)
SvNVX Returns the raw value in the SV’s NV slot, without checks or
conversions. Only use when you are sure SvNOK is true. See
also "SvNV()".
NV SvNVX(SV* sv)
SvOK Returns a boolean indicating whether the value is an SV. It
also tells whether the value is defined or not.
bool SvOK(SV* sv)
SvOOK Returns a boolean indicating whether the SvIVX is a valid off-
set value for the SvPVX. This hack is used internally to speed
up removal of characters from the beginning of a SvPV. When
SvOOK is true, then the start of the allocated string buffer is
really (SvPVX - SvIVX).
bool SvOOK(SV* sv)
SvPOK Returns a boolean indicating whether the SV contains a charac-
ter string.
bool SvPOK(SV* sv)
SvPOKp Returns a boolean indicating whether the SV contains a charac-
ter string. Checks the private setting. Use "SvPOK".
bool SvPOKp(SV* sv)
SvPOK_off
Unsets the PV status of an SV.
void SvPOK_off(SV* sv)
SvPOK_on
Tells an SV that it is a string.
void SvPOK_on(SV* sv)
SvPOK_only
Tells an SV that it is a string and disables all other OK bits.
Will also turn off the UTF-8 status.
void SvPOK_only(SV* sv)
SvPOK_only_UTF8
Tells an SV that it is a string and disables all other OK bits,
and leaves the UTF-8 status as it was.
void SvPOK_only_UTF8(SV* sv)
SvPV Returns a pointer to the string in the SV, or a stringified
form of the SV if the SV does not contain a string. The SV may
cache the stringified version becoming "SvPOK". Handles ’get’
magic. See also "SvPVx" for a version which guarantees to eval-
uate sv only once.
char* SvPV(SV* sv, STRLEN len)
SvPVbyte
Like "SvPV", but converts sv to byte representation first if
necessary.
char* SvPVbyte(SV* sv, STRLEN len)
SvPVbytex
Like "SvPV", but converts sv to byte representation first if
necessary. Guarantees to evaluate sv only once; use the more
efficient "SvPVbyte" otherwise.
char* SvPVbytex(SV* sv, STRLEN len)
SvPVbytex_force
Like "SvPV_force", but converts sv to byte representation first
if necessary. Guarantees to evaluate sv only once; use the
more efficient "SvPVbyte_force" otherwise.
char* SvPVbytex_force(SV* sv, STRLEN len)
SvPVbyte_force
Like "SvPV_force", but converts sv to byte representation first
if necessary.
char* SvPVbyte_force(SV* sv, STRLEN len)
SvPVbyte_nolen
Like "SvPV_nolen", but converts sv to byte representation first
if necessary.
char* SvPVbyte_nolen(SV* sv)
SvPVutf8
Like "SvPV", but converts sv to utf8 first if necessary.
char* SvPVutf8(SV* sv, STRLEN len)
SvPVutf8x
Like "SvPV", but converts sv to utf8 first if necessary. Guar-
antees to evaluate sv only once; use the more efficient
"SvPVutf8" otherwise.
char* SvPVutf8x(SV* sv, STRLEN len)
SvPVutf8x_force
Like "SvPV_force", but converts sv to utf8 first if necessary.
Guarantees to evaluate sv only once; use the more efficient
"SvPVutf8_force" otherwise.
char* SvPVutf8x_force(SV* sv, STRLEN len)
SvPVutf8_force
Like "SvPV_force", but converts sv to utf8 first if necessary.
char* SvPVutf8_force(SV* sv, STRLEN len)
SvPVutf8_nolen
Like "SvPV_nolen", but converts sv to utf8 first if necessary.
char* SvPVutf8_nolen(SV* sv)
SvPVx A version of "SvPV" which guarantees to evaluate sv only once.
char* SvPVx(SV* sv, STRLEN len)
SvPVX Returns a pointer to the physical string in the SV. The SV
must contain a string.
char* SvPVX(SV* sv)
SvPV_force
Like "SvPV" but will force the SV into containing just a string
("SvPOK_only"). You want force if you are going to update the
"SvPVX" directly.
char* SvPV_force(SV* sv, STRLEN len)
SvPV_force_nomg
Like "SvPV" but will force the SV into containing just a string
("SvPOK_only"). You want force if you are going to update the
"SvPVX" directly. Doesn’t process magic.
char* SvPV_force_nomg(SV* sv, STRLEN len)
SvPV_nolen
Returns a pointer to the string in the SV, or a stringified
form of the SV if the SV does not contain a string. The SV may
cache the stringified form becoming "SvPOK". Handles ’get’
magic.
char* SvPV_nolen(SV* sv)
SvREFCNT
Returns the value of the object’s reference count.
U32 SvREFCNT(SV* sv)
SvREFCNT_dec
Decrements the reference count of the given SV.
void SvREFCNT_dec(SV* sv)
SvREFCNT_inc
Increments the reference count of the given SV.
SV* SvREFCNT_inc(SV* sv)
SvROK Tests if the SV is an RV.
bool SvROK(SV* sv)
SvROK_off
Unsets the RV status of an SV.
void SvROK_off(SV* sv)
SvROK_on
Tells an SV that it is an RV.
void SvROK_on(SV* sv)
SvRV Dereferences an RV to return the SV.
SV* SvRV(SV* sv)
SvSTASH Returns the stash of the SV.
HV* SvSTASH(SV* sv)
SvTAINT Taints an SV if tainting is enabled.
void SvTAINT(SV* sv)
SvTAINTED
Checks to see if an SV is tainted. Returns TRUE if it is, FALSE
if not.
bool SvTAINTED(SV* sv)
SvTAINTED_off
Untaints an SV. Be very careful with this routine, as it short-
circuits some of Perl’s fundamental security features. XS mod-
ule authors should not use this function unless they fully
understand all the implications of unconditionally untainting
the value. Untainting should be done in the standard perl fash-
ion, via a carefully crafted regexp, rather than directly
untainting variables.
void SvTAINTED_off(SV* sv)
SvTAINTED_on
Marks an SV as tainted if tainting is enabled.
void SvTAINTED_on(SV* sv)
SvTRUE Returns a boolean indicating whether Perl would evaluate the SV
as true or false, defined or undefined. Does not handle ’get’
magic.
bool SvTRUE(SV* sv)
SvTYPE Returns the type of the SV. See "svtype".
svtype SvTYPE(SV* sv)
SvUOK Returns a boolean indicating whether the SV contains an
unsigned integer.
void SvUOK(SV* sv)
SvUPGRADE
Used to upgrade an SV to a more complex form. Uses
"sv_upgrade" to perform the upgrade if necessary. See
"svtype".
void SvUPGRADE(SV* sv, svtype type)
SvUTF8 Returns a boolean indicating whether the SV contains UTF-8
encoded data.
bool SvUTF8(SV* sv)
SvUTF8_off
Unsets the UTF-8 status of an SV.
void SvUTF8_off(SV *sv)
SvUTF8_on
Turn on the UTF-8 status of an SV (the data is not changed,
just the flag). Do not use frivolously.
void SvUTF8_on(SV *sv)
SvUV Coerces the given SV to an unsigned integer and returns it.
See "SvUVx" for a version which guarantees to evaluate sv only
once.
UV SvUV(SV* sv)
SvUVx Coerces the given SV to an unsigned integer and returns it.
Guarantees to evaluate sv only once. Use the more efficient
"SvUV" otherwise.
UV SvUVx(SV* sv)
SvUVX Returns the raw value in the SV’s UV slot, without checks or
conversions. Only use when you are sure SvIOK is true. See
also "SvUV()".
UV SvUVX(SV* sv)
sv_2bool
This function is only called on magical items, and is only used
by sv_true() or its macro equivalent.
bool sv_2bool(SV* sv)
sv_2cv Using various gambits, try to get a CV from an SV; in addition,
try if possible to set *st and *gvp to the stash and GV
associated with it.
CV* sv_2cv(SV* sv, HV** st, GV** gvp, I32 lref)
sv_2io Using various gambits, try to get an IO from an SV: the IO slot
if its a GV; or the recursive result if we’re an RV; or the IO
slot of the symbol named after the PV if we’re a string.
IO* sv_2io(SV* sv)
sv_2iv Return the integer value of an SV, doing any necessary string
conversion, magic etc. Normally used via the "SvIV(sv)" and
"SvIVx(sv)" macros.
IV sv_2iv(SV* sv)
sv_2mortal
Marks an existing SV as mortal. The SV will be destroyed
"soon", either by an explicit call to FREETMPS, or by an
implicit call at places such as statement boundaries. SvTEMP()
is turned on which means that the SV’s string buffer can be
"stolen" if this SV is copied. See also "sv_newmortal" and
"sv_mortalcopy".
SV* sv_2mortal(SV* sv)
sv_2nv Return the num value of an SV, doing any necessary string or
integer conversion, magic etc. Normally used via the "SvNV(sv)"
and "SvNVx(sv)" macros.
NV sv_2nv(SV* sv)
sv_2pvbyte
Return a pointer to the byte-encoded representation of the SV,
and set *lp to its length. May cause the SV to be downgraded
from UTF-8 as a side-effect.
Usually accessed via the "SvPVbyte" macro.
char* sv_2pvbyte(SV* sv, STRLEN* lp)
sv_2pvbyte_nolen
Return a pointer to the byte-encoded representation of the SV.
May cause the SV to be downgraded from UTF-8 as a side-effect.
Usually accessed via the "SvPVbyte_nolen" macro.
char* sv_2pvbyte_nolen(SV* sv)
sv_2pvutf8
Return a pointer to the UTF-8-encoded representation of the SV,
and set *lp to its length. May cause the SV to be upgraded to
UTF-8 as a side-effect.
Usually accessed via the "SvPVutf8" macro.
char* sv_2pvutf8(SV* sv, STRLEN* lp)
sv_2pvutf8_nolen
Return a pointer to the UTF-8-encoded representation of the SV.
May cause the SV to be upgraded to UTF-8 as a side-effect.
Usually accessed via the "SvPVutf8_nolen" macro.
char* sv_2pvutf8_nolen(SV* sv)
sv_2pv_flags
Returns a pointer to the string value of an SV, and sets *lp to
its length. If flags includes SV_GMAGIC, does an mg_get()
first. Coerces sv to a string if necessary. Normally invoked
via the "SvPV_flags" macro. "sv_2pv()" and "sv_2pv_nomg" usu-
ally end up here too.
char* sv_2pv_flags(SV* sv, STRLEN* lp, I32 flags)
sv_2pv_nolen
Like "sv_2pv()", but doesn’t return the length too. You should
usually use the macro wrapper "SvPV_nolen(sv)" instead.
char* sv_2pv_nolen(SV* sv)
sv_2uv Return the unsigned integer value of an SV, doing any necessary
string conversion, magic etc. Normally used via the "SvUV(sv)"
and "SvUVx(sv)" macros.
UV sv_2uv(SV* sv)
sv_backoff
Remove any string offset. You should normally use the
"SvOOK_off" macro wrapper instead.
int sv_backoff(SV* sv)
sv_bless
Blesses an SV into a specified package. The SV must be an RV.
The package must be designated by its stash (see
"gv_stashpv()"). The reference count of the SV is unaffected.
SV* sv_bless(SV* sv, HV* stash)
sv_catpv
Concatenates the string onto the end of the string which is in
the SV. If the SV has the UTF-8 status set, then the bytes
appended should be valid UTF-8. Handles ’get’ magic, but not
’set’ magic. See "sv_catpv_mg".
void sv_catpv(SV* sv, const char* ptr)
sv_catpvf
Processes its arguments like "sprintf" and appends the format-
ted output to an SV. If the appended data contains "wide"
characters (including, but not limited to, SVs with a UTF-8 PV
formatted with %s, and characters >255 formatted with %c), the
original SV might get upgraded to UTF-8. Handles ’get’ magic,
but not ’set’ magic. See "sv_catpvf_mg".
void sv_catpvf(SV* sv, const char* pat, ...)
sv_catpvf_mg
Like "sv_catpvf", but also handles ’set’ magic.
void sv_catpvf_mg(SV *sv, const char* pat, ...)
sv_catpvn
Concatenates the string onto the end of the string which is in
the SV. The "len" indicates number of bytes to copy. If the
SV has the UTF-8 status set, then the bytes appended should be
valid UTF-8. Handles ’get’ magic, but not ’set’ magic. See
"sv_catpvn_mg".
void sv_catpvn(SV* sv, const char* ptr, STRLEN len)
sv_catpvn_flags
Concatenates the string onto the end of the string which is in
the SV. The "len" indicates number of bytes to copy. If the
SV has the UTF-8 status set, then the bytes appended should be
valid UTF-8. If "flags" has "SV_GMAGIC" bit set, will "mg_get"
on "dsv" if appropriate, else not. "sv_catpvn" and "sv_cat-
pvn_nomg" are implemented in terms of this function.
void sv_catpvn_flags(SV* sv, const char* ptr, STRLEN len, I32 flags)
sv_catpvn_mg
Like "sv_catpvn", but also handles ’set’ magic.
void sv_catpvn_mg(SV *sv, const char *ptr, STRLEN len)
sv_catpvn_nomg
Like "sv_catpvn" but doesn’t process magic.
void sv_catpvn_nomg(SV* sv, const char* ptr, STRLEN len)
sv_catpv_mg
Like "sv_catpv", but also handles ’set’ magic.
void sv_catpv_mg(SV *sv, const char *ptr)
sv_catsv
Concatenates the string from SV "ssv" onto the end of the
string in SV "dsv". Modifies "dsv" but not "ssv". Handles
’get’ magic, but not ’set’ magic. See "sv_catsv_mg".
void sv_catsv(SV* dsv, SV* ssv)
sv_catsv_flags
Concatenates the string from SV "ssv" onto the end of the
string in SV "dsv". Modifies "dsv" but not "ssv". If "flags"
has "SV_GMAGIC" bit set, will "mg_get" on the SVs if appropri-
ate, else not. "sv_catsv" and "sv_catsv_nomg" are implemented
in terms of this function.
void sv_catsv_flags(SV* dsv, SV* ssv, I32 flags)
sv_catsv_mg
Like "sv_catsv", but also handles ’set’ magic.
void sv_catsv_mg(SV *dstr, SV *sstr)
sv_catsv_nomg
Like "sv_catsv" but doesn’t process magic.
void sv_catsv_nomg(SV* dsv, SV* ssv)
sv_chop Efficient removal of characters from the beginning of the
string buffer. SvPOK(sv) must be true and the "ptr" must be a
pointer to somewhere inside the string buffer. The "ptr"
becomes the first character of the adjusted string. Uses the
"OOK hack". Beware: after this function returns, "ptr" and
SvPVX(sv) may no longer refer to the same chunk of data.
void sv_chop(SV* sv, char* ptr)
sv_clear
Clear an SV: call any destructors, free up any memory used by
the body, and free the body itself. The SV’s head is not freed,
although its type is set to all 1’s so that it won’t inadver-
tently be assumed to be live during global destruction etc.
This function should only be called when REFCNT is zero. Most
of the time you’ll want to call "sv_free()" (or its macro wrap-
per "SvREFCNT_dec") instead.
void sv_clear(SV* sv)
sv_cmp Compares the strings in two SVs. Returns -1, 0, or 1 indicat-
ing whether the string in "sv1" is less than, equal to, or
greater than the string in "sv2". Is UTF-8 and ’use bytes’
aware, handles get magic, and will coerce its args to strings
if necessary. See also "sv_cmp_locale".
I32 sv_cmp(SV* sv1, SV* sv2)
sv_cmp_locale
Compares the strings in two SVs in a locale-aware manner. Is
UTF-8 and ’use bytes’ aware, handles get magic, and will coerce
its args to strings if necessary. See also "sv_cmp_locale".
See also "sv_cmp".
I32 sv_cmp_locale(SV* sv1, SV* sv2)
sv_collxfrm
Add Collate Transform magic to an SV if it doesn’t already have
it.
Any scalar variable may carry PERL_MAGIC_collxfrm magic that
contains the scalar data of the variable, but transformed to
such a format that a normal memory comparison can be used to
compare the data according to the locale settings.
char* sv_collxfrm(SV* sv, STRLEN* nxp)
sv_copypv
Copies a stringified representation of the source SV into the
destination SV. Automatically performs any necessary mg_get
and coercion of numeric values into strings. Guaranteed to
preserve UTF-8 flag even from overloaded objects. Similar in
nature to sv_2pv[_flags] but operates directly on an SV instead
of just the string. Mostly uses sv_2pv_flags to do its work,
except when that would lose the UTF-8’ness of the PV.
void sv_copypv(SV* dsv, SV* ssv)
sv_dec Auto-decrement of the value in the SV, doing string to numeric
conversion if necessary. Handles ’get’ magic.
void sv_dec(SV* sv)
sv_derived_from
Returns a boolean indicating whether the SV is derived from the
specified class. This is the function that implements "UNIVER-
SAL::isa". It works for class names as well as for objects.
bool sv_derived_from(SV* sv, const char* name)
sv_eq Returns a boolean indicating whether the strings in the two SVs
are identical. Is UTF-8 and ’use bytes’ aware, handles get
magic, and will coerce its args to strings if necessary.
I32 sv_eq(SV* sv1, SV* sv2)
sv_force_normal
Undo various types of fakery on an SV: if the PV is a shared
string, make a private copy; if we’re a ref, stop refing; if
we’re a glob, downgrade to an xpvmg. See also "sv_force_nor-
mal_flags".
void sv_force_normal(SV *sv)
sv_force_normal_flags
Undo various types of fakery on an SV: if the PV is a shared
string, make a private copy; if we’re a ref, stop refing; if
we’re a glob, downgrade to an xpvmg. The "flags" parameter gets
passed to "sv_unref_flags()" when unrefing. "sv_force_normal"
calls this function with flags set to 0.
void sv_force_normal_flags(SV *sv, U32 flags)
sv_free Decrement an SV’s reference count, and if it drops to zero,
call "sv_clear" to invoke destructors and free up any memory
used by the body; finally, deallocate the SV’s head itself.
Normally called via a wrapper macro "SvREFCNT_dec".
void sv_free(SV* sv)
sv_gets Get a line from the filehandle and store it into the SV,
optionally appending to the currently-stored string.
char* sv_gets(SV* sv, PerlIO* fp, I32 append)
sv_grow Expands the character buffer in the SV. If necessary, uses
"sv_unref" and upgrades the SV to "SVt_PV". Returns a pointer
to the character buffer. Use the "SvGROW" wrapper instead.
char* sv_grow(SV* sv, STRLEN newlen)
sv_inc Auto-increment of the value in the SV, doing string to numeric
conversion if necessary. Handles ’get’ magic.
void sv_inc(SV* sv)
sv_insert
Inserts a string at the specified offset/length within the SV.
Similar to the Perl substr() function.
void sv_insert(SV* bigsv, STRLEN offset, STRLEN len, char* little, STRLEN littlelen)
sv_isa Returns a boolean indicating whether the SV is blessed into the
specified class. This does not check for subtypes; use
"sv_derived_from" to verify an inheritance relationship.
int sv_isa(SV* sv, const char* name)
sv_isobject
Returns a boolean indicating whether the SV is an RV pointing
to a blessed object. If the SV is not an RV, or if the object
is not blessed, then this will return false.
int sv_isobject(SV* sv)
sv_iv A private implementation of the "SvIVx" macro for compilers
which can’t cope with complex macro expressions. Always use the
macro instead.
IV sv_iv(SV* sv)
sv_len Returns the length of the string in the SV. Handles magic and
type coercion. See also "SvCUR", which gives raw access to the
xpv_cur slot.
STRLEN sv_len(SV* sv)
sv_len_utf8
Returns the number of characters in the string in an SV, count-
ing wide UTF-8 bytes as a single character. Handles magic and
type coercion.
STRLEN sv_len_utf8(SV* sv)
sv_magic
Adds magic to an SV. First upgrades "sv" to type "SVt_PVMG" if
necessary, then adds a new magic item of type "how" to the head
of the magic list.
See "sv_magicext" (which "sv_magic" now calls) for a descrip-
tion of the handling of the "name" and "namlen" arguments.
void sv_magic(SV* sv, SV* obj, int how, const char* name, I32 namlen)
sv_magicext
Adds magic to an SV, upgrading it if necessary. Applies the
supplied vtable and returns a pointer to the magic added.
Note that "sv_magicext" will allow things that "sv_magic" will
not. In particular, you can add magic to SvREADONLY SVs, and
add more than one instance of the same ’how’.
If "namlen" is greater than zero then a "savepvn" copy of
"name" is stored, if "namlen" is zero then "name" is stored as-
is and - as another special case - if "(name && namlen ==
HEf_SVKEY)" then "name" is assumed to contain an "SV*" and is
stored as-is with its REFCNT incremented.
(This is now used as a subroutine by "sv_magic".)
MAGIC * sv_magicext(SV* sv, SV* obj, int how, MGVTBL *vtbl, const char* name, I32 namlen )
sv_mortalcopy
Creates a new SV which is a copy of the original SV (using
"sv_setsv"). The new SV is marked as mortal. It will be
destroyed "soon", either by an explicit call to FREETMPS, or by
an implicit call at places such as statement boundaries. See
also "sv_newmortal" and "sv_2mortal".
SV* sv_mortalcopy(SV* oldsv)
sv_newmortal
Creates a new null SV which is mortal. The reference count of
the SV is set to 1. It will be destroyed "soon", either by an
explicit call to FREETMPS, or by an implicit call at places
such as statement boundaries. See also "sv_mortalcopy" and
"sv_2mortal".
SV* sv_newmortal()
sv_newref
Increment an SV’s reference count. Use the "SvREFCNT_inc()"
wrapper instead.
SV* sv_newref(SV* sv)
sv_nv A private implementation of the "SvNVx" macro for compilers
which can’t cope with complex macro expressions. Always use the
macro instead.
NV sv_nv(SV* sv)
sv_pos_b2u
Converts the value pointed to by offsetp from a count of bytes
from the start of the string, to a count of the equivalent num-
ber of UTF-8 chars. Handles magic and type coercion.
void sv_pos_b2u(SV* sv, I32* offsetp)
sv_pos_u2b
Converts the value pointed to by offsetp from a count of UTF-8
chars from the start of the string, to a count of the equiva-
lent number of bytes; if lenp is non-zero, it does the same to
lenp, but this time starting from the offset, rather than from
the start of the string. Handles magic and type coercion.
void sv_pos_u2b(SV* sv, I32* offsetp, I32* lenp)
sv_pv Use the "SvPV_nolen" macro instead
char* sv_pv(SV *sv)
sv_pvbyte
Use "SvPVbyte_nolen" instead.
char* sv_pvbyte(SV *sv)
sv_pvbyten
A private implementation of the "SvPVbyte" macro for compilers
which can’t cope with complex macro expressions. Always use the
macro instead.
char* sv_pvbyten(SV *sv, STRLEN *len)
sv_pvbyten_force
A private implementation of the "SvPVbytex_force" macro for
compilers which can’t cope with complex macro expressions.
Always use the macro instead.
char* sv_pvbyten_force(SV* sv, STRLEN* lp)
sv_pvn A private implementation of the "SvPV" macro for compilers
which can’t cope with complex macro expressions. Always use the
macro instead.
char* sv_pvn(SV *sv, STRLEN *len)
sv_pvn_force
Get a sensible string out of the SV somehow. A private imple-
mentation of the "SvPV_force" macro for compilers which can’t
cope with complex macro expressions. Always use the macro
instead.
char* sv_pvn_force(SV* sv, STRLEN* lp)
sv_pvn_force_flags
Get a sensible string out of the SV somehow. If "flags" has
"SV_GMAGIC" bit set, will "mg_get" on "sv" if appropriate, else
not. "sv_pvn_force" and "sv_pvn_force_nomg" are implemented in
terms of this function. You normally want to use the various
wrapper macros instead: see "SvPV_force" and "SvPV_force_nomg"
char* sv_pvn_force_flags(SV* sv, STRLEN* lp, I32 flags)
sv_pvutf8
Use the "SvPVutf8_nolen" macro instead
char* sv_pvutf8(SV *sv)
sv_pvutf8n
A private implementation of the "SvPVutf8" macro for compilers
which can’t cope with complex macro expressions. Always use the
macro instead.
char* sv_pvutf8n(SV *sv, STRLEN *len)
sv_pvutf8n_force
A private implementation of the "SvPVutf8_force" macro for com-
pilers which can’t cope with complex macro expressions. Always
use the macro instead.
char* sv_pvutf8n_force(SV* sv, STRLEN* lp)
sv_reftype
Returns a string describing what the SV is a reference to.
char* sv_reftype(SV* sv, int ob)
sv_replace
Make the first argument a copy of the second, then delete the
original. The target SV physically takes over ownership of the
body of the source SV and inherits its flags; however, the tar-
get keeps any magic it owns, and any magic in the source is
discarded. Note that this is a rather specialist SV copying
operation; most of the time you’ll want to use "sv_setsv" or
one of its many macro front-ends.
void sv_replace(SV* sv, SV* nsv)
sv_report_used
Dump the contents of all SVs not yet freed. (Debugging aid).
void sv_report_used()
sv_reset
Underlying implementation for the "reset" Perl function. Note
that the perl-level function is vaguely deprecated.
void sv_reset(char* s, HV* stash)
sv_rvweaken
Weaken a reference: set the "SvWEAKREF" flag on this RV; give
the referred-to SV "PERL_MAGIC_backref" magic if it hasn’t
already; and push a back-reference to this RV onto the array of
backreferences associated with that magic.
SV* sv_rvweaken(SV *sv)
sv_setiv
Copies an integer into the given SV, upgrading first if neces-
sary. Does not handle ’set’ magic. See also "sv_setiv_mg".
void sv_setiv(SV* sv, IV num)
sv_setiv_mg
Like "sv_setiv", but also handles ’set’ magic.
void sv_setiv_mg(SV *sv, IV i)
sv_setnv
Copies a double into the given SV, upgrading first if neces-
sary. Does not handle ’set’ magic. See also "sv_setnv_mg".
void sv_setnv(SV* sv, NV num)
sv_setnv_mg
Like "sv_setnv", but also handles ’set’ magic.
void sv_setnv_mg(SV *sv, NV num)
sv_setpv
Copies a string into an SV. The string must be null-termi-
nated. Does not handle ’set’ magic. See "sv_setpv_mg".
void sv_setpv(SV* sv, const char* ptr)
sv_setpvf
Works like "sv_catpvf" but copies the text into the SV instead
of appending it. Does not handle ’set’ magic. See "sv_set-
pvf_mg".
void sv_setpvf(SV* sv, const char* pat, ...)
sv_setpvf_mg
Like "sv_setpvf", but also handles ’set’ magic.
void sv_setpvf_mg(SV *sv, const char* pat, ...)
sv_setpviv
Copies an integer into the given SV, also updating its string
value. Does not handle ’set’ magic. See "sv_setpviv_mg".
void sv_setpviv(SV* sv, IV num)
sv_setpviv_mg
Like "sv_setpviv", but also handles ’set’ magic.
void sv_setpviv_mg(SV *sv, IV iv)
sv_setpvn
Copies a string into an SV. The "len" parameter indicates the
number of bytes to be copied. If the "ptr" argument is NULL
the SV will become undefined. Does not handle ’set’ magic.
See "sv_setpvn_mg".
void sv_setpvn(SV* sv, const char* ptr, STRLEN len)
sv_setpvn_mg
Like "sv_setpvn", but also handles ’set’ magic.
void sv_setpvn_mg(SV *sv, const char *ptr, STRLEN len)
sv_setpv_mg
Like "sv_setpv", but also handles ’set’ magic.
void sv_setpv_mg(SV *sv, const char *ptr)
sv_setref_iv
Copies an integer into a new SV, optionally blessing the SV.
The "rv" argument will be upgraded to an RV. That RV will be
modified to point to the new SV. The "classname" argument
indicates the package for the blessing. Set "classname" to
"Nullch" to avoid the blessing. The new SV will have a refer-
ence count of 1, and the RV will be returned.
SV* sv_setref_iv(SV* rv, const char* classname, IV iv)
sv_setref_nv
Copies a double into a new SV, optionally blessing the SV. The
"rv" argument will be upgraded to an RV. That RV will be modi-
fied to point to the new SV. The "classname" argument indi-
cates the package for the blessing. Set "classname" to
"Nullch" to avoid the blessing. The new SV will have a refer-
ence count of 1, and the RV will be returned.
SV* sv_setref_nv(SV* rv, const char* classname, NV nv)
sv_setref_pv
Copies a pointer into a new SV, optionally blessing the SV.
The "rv" argument will be upgraded to an RV. That RV will be
modified to point to the new SV. If the "pv" argument is NULL
then "PL_sv_undef" will be placed into the SV. The "classname"
argument indicates the package for the blessing. Set "class-
name" to "Nullch" to avoid the blessing. The new SV will have
a reference count of 1, and the RV will be returned.
Do not use with other Perl types such as HV, AV, SV, CV,
because those objects will become corrupted by the pointer copy
process.
Note that "sv_setref_pvn" copies the string while this copies
the pointer.
SV* sv_setref_pv(SV* rv, const char* classname, void* pv)
sv_setref_pvn
Copies a string into a new SV, optionally blessing the SV. The
length of the string must be specified with "n". The "rv"
argument will be upgraded to an RV. That RV will be modified
to point to the new SV. The "classname" argument indicates the
package for the blessing. Set "classname" to "Nullch" to avoid
the blessing. The new SV will have a reference count of 1, and
the RV will be returned.
Note that "sv_setref_pv" copies the pointer while this copies
the string.
SV* sv_setref_pvn(SV* rv, const char* classname, char* pv, STRLEN n)
sv_setref_uv
Copies an unsigned integer into a new SV, optionally blessing
the SV. The "rv" argument will be upgraded to an RV. That RV
will be modified to point to the new SV. The "classname" argu-
ment indicates the package for the blessing. Set "classname"
to "Nullch" to avoid the blessing. The new SV will have a ref-
erence count of 1, and the RV will be returned.
SV* sv_setref_uv(SV* rv, const char* classname, UV uv)
sv_setsv
Copies the contents of the source SV "ssv" into the destination
SV "dsv". The source SV may be destroyed if it is mortal, so
don’t use this function if the source SV needs to be reused.
Does not handle ’set’ magic. Loosely speaking, it performs a
copy-by-value, obliterating any previous content of the desti-
nation.
You probably want to use one of the assortment of wrappers,
such as "SvSetSV", "SvSetSV_nosteal", "SvSetMagicSV" and
"SvSetMagicSV_nosteal".
void sv_setsv(SV* dsv, SV* ssv)
sv_setsv_flags
Copies the contents of the source SV "ssv" into the destination
SV "dsv". The source SV may be destroyed if it is mortal, so
don’t use this function if the source SV needs to be reused.
Does not handle ’set’ magic. Loosely speaking, it performs a
copy-by-value, obliterating any previous content of the desti-
nation. If the "flags" parameter has the "SV_GMAGIC" bit set,
will "mg_get" on "ssv" if appropriate, else not. If the "flags"
parameter has the "NOSTEAL" bit set then the buffers of temps
will not be stolen. <sv_setsv> and "sv_setsv_nomg" are imple-
mented in terms of this function.
You probably want to use one of the assortment of wrappers,
such as "SvSetSV", "SvSetSV_nosteal", "SvSetMagicSV" and
"SvSetMagicSV_nosteal".
This is the primary function for copying scalars, and most
other copy-ish functions and macros use this underneath.
void sv_setsv_flags(SV* dsv, SV* ssv, I32 flags)
sv_setsv_mg
Like "sv_setsv", but also handles ’set’ magic.
void sv_setsv_mg(SV *dstr, SV *sstr)
sv_setsv_nomg
Like "sv_setsv" but doesn’t process magic.
void sv_setsv_nomg(SV* dsv, SV* ssv)
sv_setuv
Copies an unsigned integer into the given SV, upgrading first
if necessary. Does not handle ’set’ magic. See also
"sv_setuv_mg".
void sv_setuv(SV* sv, UV num)
sv_setuv_mg
Like "sv_setuv", but also handles ’set’ magic.
void sv_setuv_mg(SV *sv, UV u)
sv_taint
Taint an SV. Use "SvTAINTED_on" instead.
void sv_taint(SV* sv)
sv_tainted
Test an SV for taintedness. Use "SvTAINTED" instead.
bool sv_tainted(SV* sv)
sv_true Returns true if the SV has a true value by Perl’s rules. Use
the "SvTRUE" macro instead, which may call "sv_true()" or may
instead use an in-line version.
I32 sv_true(SV *sv)
sv_unmagic
Removes all magic of type "type" from an SV.
int sv_unmagic(SV* sv, int type)
sv_unref
Unsets the RV status of the SV, and decrements the reference
count of whatever was being referenced by the RV. This can
almost be thought of as a reversal of "newSVrv". This is
"sv_unref_flags" with the "flag" being zero. See "SvROK_off".
void sv_unref(SV* sv)
sv_unref_flags
Unsets the RV status of the SV, and decrements the reference
count of whatever was being referenced by the RV. This can
almost be thought of as a reversal of "newSVrv". The "cflags"
argument can contain "SV_IMMEDIATE_UNREF" to force the refer-
ence count to be decremented (otherwise the decrementing is
conditional on the reference count being different from one or
the reference being a readonly SV). See "SvROK_off".
void sv_unref_flags(SV* sv, U32 flags)
sv_untaint
Untaint an SV. Use "SvTAINTED_off" instead.
void sv_untaint(SV* sv)
sv_upgrade
Upgrade an SV to a more complex form. Generally adds a new
body type to the SV, then copies across as much information as
possible from the old body. You generally want to use the
"SvUPGRADE" macro wrapper. See also "svtype".
bool sv_upgrade(SV* sv, U32 mt)
sv_usepvn
Tells an SV to use "ptr" to find its string value. Normally
the string is stored inside the SV but sv_usepvn allows the SV
to use an outside string. The "ptr" should point to memory
that was allocated by "malloc". The string length, "len", must
be supplied. This function will realloc the memory pointed to
by "ptr", so that pointer should not be freed or used by the
programmer after giving it to sv_usepvn. Does not handle ’set’
magic. See "sv_usepvn_mg".
void sv_usepvn(SV* sv, char* ptr, STRLEN len)
sv_usepvn_mg
Like "sv_usepvn", but also handles ’set’ magic.
void sv_usepvn_mg(SV *sv, char *ptr, STRLEN len)
sv_utf8_decode
If the PV of the SV is an octet sequence in UTF-8 and contains
a multiple-byte character, the "SvUTF8" flag is turned on so
that it looks like a character. If the PV contains only single-
byte characters, the "SvUTF8" flag stays being off. Scans PV
for validity and returns false if the PV is invalid UTF-8.
NOTE: this function is experimental and may change or be
removed without notice.
bool sv_utf8_decode(SV *sv)
sv_utf8_downgrade
Attempts to convert the PV of an SV from characters to bytes.
If the PV contains a character beyond byte, this conversion
will fail; in this case, either returns false or, if "fail_ok"
is not true, croaks.
This is not as a general purpose Unicode to byte encoding
interface: use the Encode extension for that.
NOTE: this function is experimental and may change or be
removed without notice.
bool sv_utf8_downgrade(SV *sv, bool fail_ok)
sv_utf8_encode
Converts the PV of an SV to UTF-8, but then turns the "SvUTF8"
flag off so that it looks like octets again.
void sv_utf8_encode(SV *sv)
sv_utf8_upgrade
Converts the PV of an SV to its UTF-8-encoded form. Forces the
SV to string form if it is not already. Always sets the SvUTF8
flag to avoid future validity checks even if all the bytes have
hibit clear.
This is not as a general purpose byte encoding to Unicode
interface: use the Encode extension for that.
STRLEN sv_utf8_upgrade(SV *sv)
sv_utf8_upgrade_flags
Converts the PV of an SV to its UTF-8-encoded form. Forces the
SV to string form if it is not already. Always sets the SvUTF8
flag to avoid future validity checks even if all the bytes have
hibit clear. If "flags" has "SV_GMAGIC" bit set, will "mg_get"
on "sv" if appropriate, else not. "sv_utf8_upgrade" and
"sv_utf8_upgrade_nomg" are implemented in terms of this func-
tion.
This is not as a general purpose byte encoding to Unicode
interface: use the Encode extension for that.
STRLEN sv_utf8_upgrade_flags(SV *sv, I32 flags)
sv_uv A private implementation of the "SvUVx" macro for compilers
which can’t cope with complex macro expressions. Always use the
macro instead.
UV sv_uv(SV* sv)
sv_vcatpvf
Processes its arguments like "vsprintf" and appends the format-
ted output to an SV. Does not handle ’set’ magic. See
"sv_vcatpvf_mg".
Usually used via its frontend "sv_catpvf".
void sv_vcatpvf(SV* sv, const char* pat, va_list* args)
sv_vcatpvfn
Processes its arguments like "vsprintf" and appends the format-
ted output to an SV. Uses an array of SVs if the C style vari-
able argument list is missing (NULL). When running with taint
checks enabled, indicates via "maybe_tainted" if results are
untrustworthy (often due to the use of locales).
Usually used via one of its frontends "sv_vcatpvf" and
"sv_vcatpvf_mg".
void sv_vcatpvfn(SV* sv, const char* pat, STRLEN patlen, va_list* args, SV** svargs, I32 svmax, bool *maybe_tainted)
sv_vcatpvf_mg
Like "sv_vcatpvf", but also handles ’set’ magic.
Usually used via its frontend "sv_catpvf_mg".
void sv_vcatpvf_mg(SV* sv, const char* pat, va_list* args)
sv_vsetpvf
Works like "sv_vcatpvf" but copies the text into the SV instead
of appending it. Does not handle ’set’ magic. See "sv_vset-
pvf_mg".
Usually used via its frontend "sv_setpvf".
void sv_vsetpvf(SV* sv, const char* pat, va_list* args)
sv_vsetpvfn
Works like "sv_vcatpvfn" but copies the text into the SV
instead of appending it.
Usually used via one of its frontends "sv_vsetpvf" and
"sv_vsetpvf_mg".
void sv_vsetpvfn(SV* sv, const char* pat, STRLEN patlen, va_list* args, SV** svargs, I32 svmax, bool *maybe_tainted)
sv_vsetpvf_mg
Like "sv_vsetpvf", but also handles ’set’ magic.
Usually used via its frontend "sv_setpvf_mg".
void sv_vsetpvf_mg(SV* sv, const char* pat, va_list* args)

Unicode Support

bytes_from_utf8
Converts a string "s" of length "len" from UTF-8 into byte
encoding. Unlike <utf8_to_bytes> but like "bytes_to_utf8",
returns a pointer to the newly-created string, and updates
"len" to contain the new length. Returns the original string
if no conversion occurs, "len" is unchanged. Do nothing if
"is_utf8" points to 0. Sets "is_utf8" to 0 if "s" is converted
or contains all 7bit characters.
NOTE: this function is experimental and may change or be
removed without notice.
U8* bytes_from_utf8(U8 *s, STRLEN *len, bool *is_utf8)
bytes_to_utf8
Converts a string "s" of length "len" from ASCII into UTF-8
encoding. Returns a pointer to the newly-created string, and
sets "len" to reflect the new length.
If you want to convert to UTF-8 from other encodings than
ASCII, see sv_recode_to_utf8().
NOTE: this function is experimental and may change or be
removed without notice.
U8* bytes_to_utf8(U8 *s, STRLEN *len)
ibcmp_utf8
Return true if the strings s1 and s2 differ case-insensitively,
false if not (if they are equal case-insensitively). If u1 is
true, the string s1 is assumed to be in UTF-8-encoded Unicode.
If u2 is true, the string s2 is assumed to be in UTF-8-encoded
Unicode. If u1 or u2 are false, the respective string is
assumed to be in native 8-bit encoding.
If the pe1 and pe2 are non-NULL, the scanning pointers will be
copied in there (they will point at the beginning of the next
character). If the pointers behind pe1 or pe2 are non-NULL,
they are the end pointers beyond which scanning will not con-
tinue under any circumstances. If the byte lengths l1 and l2
are non-zero, s1+l1 and s2+l2 will be used as goal end pointers
that will also stop the scan, and which qualify towards defin-
ing a successful match: all the scans that define an explicit
length must reach their goal pointers for a match to succeed).
For case-insensitiveness, the "casefolding" of Unicode is used
instead of upper/lowercasing both the characters, see
http://www.unicode.org/unicode/reports/tr21/ (Case Mappings).
I32 ibcmp_utf8(const char* a, char **pe1, UV l1, bool u1, const char* b, char **pe2, UV l2, bool u2)
is_utf8_char
Tests if some arbitrary number of bytes begins in a valid UTF-8
character. Note that an INVARIANT (i.e. ASCII) character is a
valid UTF-8 character. The actual number of bytes in the UTF-8
character will be returned if it is valid, otherwise 0.
STRLEN is_utf8_char(U8 *p)
is_utf8_string
Returns true if first "len" bytes of the given string form a
valid UTF-8 string, false otherwise. Note that ’a valid UTF-8
string’ does not mean ’a string that contains code points above
0x7F encoded in UTF-8’ because a valid ASCII string is a valid
UTF-8 string.
bool is_utf8_string(U8 *s, STRLEN len)
is_utf8_string_loc
Like is_ut8_string but store the location of the failure in the
last argument.
bool is_utf8_string_loc(U8 *s, STRLEN len, U8 **p)
pv_uni_display
Build to the scalar dsv a displayable version of the string
spv, length len, the displayable version being at most pvlim
bytes long (if longer, the rest is truncated and "..." will be
appended).
The flags argument can have UNI_DISPLAY_ISPRINT set to display
isPRINT()able characters as themselves, UNI_DISPLAY_BACKSLASH
to display the \\[nrfta\\] as the backslashed versions (like
’\n’) (UNI_DISPLAY_BACKSLASH is preferred over UNI_DIS-
PLAY_ISPRINT for \\). UNI_DISPLAY_QQ (and its alias UNI_DIS-
PLAY_REGEX) have both UNI_DISPLAY_BACKSLASH and UNI_DIS-
PLAY_ISPRINT turned on.
The pointer to the PV of the dsv is returned.
char* pv_uni_display(SV *dsv, U8 *spv, STRLEN len, STRLEN pvlim, UV flags)
sv_cat_decode
The encoding is assumed to be an Encode object, the PV of the
ssv is assumed to be octets in that encoding and decoding the
input starts from the position which (PV + *offset) pointed to.
The dsv will be concatenated the decoded UTF-8 string from ssv.
Decoding will terminate when the string tstr appears in decod-
ing output or the input ends on the PV of the ssv. The value
which the offset points will be modified to the last input
position on the ssv.
Returns TRUE if the terminator was found, else returns FALSE.
bool sv_cat_decode(SV* dsv, SV *encoding, SV *ssv, int *offset, char* tstr, int tlen)
sv_recode_to_utf8
The encoding is assumed to be an Encode object, on entry the PV
of the sv is assumed to be octets in that encoding, and the sv
will be converted into Unicode (and UTF-8).
If the sv already is UTF-8 (or if it is not POK), or if the
encoding is not a reference, nothing is done to the sv. If the
encoding is not an "Encode::XS" Encoding object, bad things
will happen. (See lib/encoding.pm and Encode).
The PV of the sv is returned.
char* sv_recode_to_utf8(SV* sv, SV *encoding)
sv_uni_display
Build to the scalar dsv a displayable version of the scalar sv,
the displayable version being at most pvlim bytes long (if
longer, the rest is truncated and "..." will be appended).
The flags argument is as in pv_uni_display().
The pointer to the PV of the dsv is returned.
char* sv_uni_display(SV *dsv, SV *ssv, STRLEN pvlim, UV flags)
to_utf8_case
The "p" contains the pointer to the UTF-8 string encoding the
character that is being converted.
The "ustrp" is a pointer to the character buffer to put the
conversion result to. The "lenp" is a pointer to the length of
the result.
The "swashp" is a pointer to the swash to use.
Both the special and normal mappings are stored lib/uni-
core/To/Foo.pl, and loaded by SWASHGET, using
lib/utf8_heavy.pl. The special (usually, but not always, a
multicharacter mapping), is tried first.
The "special" is a string like "utf8::ToSpecLower", which means
the hash %utf8::ToSpecLower. The access to the hash is through
Perl_to_utf8_case().
The "normal" is a string like "ToLower" which means the swash
%utf8::ToLower.
UV to_utf8_case(U8 *p, U8* ustrp, STRLEN *lenp, SV **swash, char *normal, char *special)
to_utf8_fold
Convert the UTF-8 encoded character at p to its foldcase ver-
sion and store that in UTF-8 in ustrp and its length in bytes
in lenp. Note that the ustrp needs to be at least
UTF8_MAXLEN_FOLD+1 bytes since the foldcase version may be
longer than the original character (up to three characters).
The first character of the foldcased version is returned (but
note, as explained above, that there may be more.)
UV to_utf8_fold(U8 *p, U8* ustrp, STRLEN *lenp)
to_utf8_lower
Convert the UTF-8 encoded character at p to its lowercase ver-
sion and store that in UTF-8 in ustrp and its length in bytes
in lenp. Note that the ustrp needs to be at least
UTF8_MAXLEN_UCLC+1 bytes since the lowercase version may be
longer than the original character (up to two characters).
The first character of the lowercased version is returned (but
note, as explained above, that there may be more.)
UV to_utf8_lower(U8 *p, U8* ustrp, STRLEN *lenp)
to_utf8_title
Convert the UTF-8 encoded character at p to its titlecase ver-
sion and store that in UTF-8 in ustrp and its length in bytes
in lenp. Note that the ustrp needs to be at least
UTF8_MAXLEN_UCLC+1 bytes since the titlecase version may be
longer than the original character (up to two characters).
The first character of the titlecased version is returned (but
note, as explained above, that there may be more.)
UV to_utf8_title(U8 *p, U8* ustrp, STRLEN *lenp)
to_utf8_upper
Convert the UTF-8 encoded character at p to its uppercase ver-
sion and store that in UTF-8 in ustrp and its length in bytes
in lenp. Note that the ustrp needs to be at least
UTF8_MAXLEN_UCLC+1 bytes since the uppercase version may be
longer than the original character (up to two characters).
The first character of the uppercased version is returned (but
note, as explained above, that there may be more.)
UV to_utf8_upper(U8 *p, U8* ustrp, STRLEN *lenp)
utf8n_to_uvchr
Returns the native character value of the first character in
the string "s" which is assumed to be in UTF-8 encoding;
"retlen" will be set to the length, in bytes, of that charac-
ter.
Allows length and flags to be passed to low level routine.
UV utf8n_to_uvchr(U8 *s, STRLEN curlen, STRLEN* retlen, U32 flags)
utf8n_to_uvuni
Bottom level UTF-8 decode routine. Returns the unicode code
point value of the first character in the string "s" which is
assumed to be in UTF-8 encoding and no longer than "curlen";
"retlen" will be set to the length, in bytes, of that charac-
ter.
If "s" does not point to a well-formed UTF-8 character, the
behaviour is dependent on the value of "flags": if it contains
UTF8_CHECK_ONLY, it is assumed that the caller will raise a
warning, and this function will silently just set "retlen" to
"-1" and return zero. If the "flags" does not contain
UTF8_CHECK_ONLY, warnings about malformations will be given,
"retlen" will be set to the expected length of the UTF-8 char-
acter in bytes, and zero will be returned.
The "flags" can also contain various flags to allow deviations
from the strict UTF-8 encoding (see utf8.h).
Most code should use utf8_to_uvchr() rather than call this
directly.
UV utf8n_to_uvuni(U8 *s, STRLEN curlen, STRLEN* retlen, U32 flags)
utf8_distance
Returns the number of UTF-8 characters between the UTF-8 point-
ers "a" and "b".
WARNING: use only if you *know* that the pointers point inside
the same UTF-8 buffer.
IV utf8_distance(U8 *a, U8 *b)
utf8_hop
Return the UTF-8 pointer "s" displaced by "off" characters,
either forward or backward.
WARNING: do not use the following unless you *know* "off" is
within the UTF-8 data pointed to by "s" *and* that on entry "s"
is aligned on the first byte of character or just after the
last byte of a character.
U8* utf8_hop(U8 *s, I32 off)
utf8_length
Return the length of the UTF-8 char encoded string "s" in char-
acters. Stops at "e" (inclusive). If "e < s" or if the scan
would end up past "e", croaks.
STRLEN utf8_length(U8* s, U8 *e)
utf8_to_bytes
Converts a string "s" of length "len" from UTF-8 into byte
encoding. Unlike "bytes_to_utf8", this over-writes the origi-
nal string, and updates len to contain the new length. Returns
zero on failure, setting "len" to -1.
NOTE: this function is experimental and may change or be
removed without notice.
U8* utf8_to_bytes(U8 *s, STRLEN *len)
utf8_to_uvchr
Returns the native character value of the first character in
the string "s" which is assumed to be in UTF-8 encoding;
"retlen" will be set to the length, in bytes, of that charac-
ter.
If "s" does not point to a well-formed UTF-8 character, zero is
returned and retlen is set, if possible, to -1.
UV utf8_to_uvchr(U8 *s, STRLEN* retlen)
utf8_to_uvuni
Returns the Unicode code point of the first character in the
string "s" which is assumed to be in UTF-8 encoding; "retlen"
will be set to the length, in bytes, of that character.
This function should only be used when returned UV is consid-
ered an index into the Unicode semantic tables (e.g. swashes).
If "s" does not point to a well-formed UTF-8 character, zero is
returned and retlen is set, if possible, to -1.
UV utf8_to_uvuni(U8 *s, STRLEN* retlen)
uvchr_to_utf8
Adds the UTF-8 representation of the Native codepoint "uv" to
the end of the string "d"; "d" should be have at least
"UTF8_MAXLEN+1" free bytes available. The return value is the
pointer to the byte after the end of the new character. In
other words,
d = uvchr_to_utf8(d, uv);
is the recommended wide native character-aware way of saying
*(d++) = uv;
U8* uvchr_to_utf8(U8 *d, UV uv)
uvuni_to_utf8_flags
Adds the UTF-8 representation of the Unicode codepoint "uv" to
the end of the string "d"; "d" should be have at least
"UTF8_MAXLEN+1" free bytes available. The return value is the
pointer to the byte after the end of the new character. In
other words,
d = uvuni_to_utf8_flags(d, uv, flags);
or, in most cases,
d = uvuni_to_utf8(d, uv);
(which is equivalent to)
d = uvuni_to_utf8_flags(d, uv, 0);
is the recommended Unicode-aware way of saying
*(d++) = uv;
U8* uvuni_to_utf8_flags(U8 *d, UV uv, UV flags)

Variables created by "xsubpp" and "xsubpp" internal functions

ax Variable which is setup by "xsubpp" to indicate the stack base
offset, used by the "ST", "XSprePUSH" and "XSRETURN" macros.
The "dMARK" macro must be called prior to setup the "MARK"
variable.
I32 ax
CLASS Variable which is setup by "xsubpp" to indicate the class name
for a C++ XS constructor. This is always a "char*". See
"THIS".
char* CLASS
dAX Sets up the "ax" variable. This is usually handled automati-
cally by "xsubpp" by calling "dXSARGS".
dAX;
dITEMS Sets up the "items" variable. This is usually handled automat-
ically by "xsubpp" by calling "dXSARGS".
dITEMS;
dXSARGS Sets up stack and mark pointers for an XSUB, calling dSP and
dMARK. Sets up the "ax" and "items" variables by calling "dAX"
and "dITEMS". This is usually handled automatically by
"xsubpp".
dXSARGS;
dXSI32 Sets up the "ix" variable for an XSUB which has aliases. This
is usually handled automatically by "xsubpp".
dXSI32;
items Variable which is setup by "xsubpp" to indicate the number of
items on the stack. See "Variable-length Parameter Lists" in
perlxs.
I32 items
ix Variable which is setup by "xsubpp" to indicate which of an
XSUB’s aliases was used to invoke it. See "The ALIAS: Keyword"
in perlxs.
I32 ix
newXSproto
Used by "xsubpp" to hook up XSUBs as Perl subs. Adds Perl pro-
totypes to the subs.
RETVAL Variable which is setup by "xsubpp" to hold the return value
for an XSUB. This is always the proper type for the XSUB. See
"The RETVAL Variable" in perlxs.
(whatever) RETVAL
ST Used to access elements on the XSUB’s stack.
SV* ST(int ix)
THIS Variable which is setup by "xsubpp" to designate the object in
a C++ XSUB. This is always the proper type for the C++ object.
See "CLASS" and "Using XS With C++" in perlxs.
(whatever) THIS
XS Macro to declare an XSUB and its C parameter list. This is
handled by "xsubpp".
XS_VERSION
The version identifier for an XS module. This is usually han-
dled automatically by "ExtUtils::MakeMaker". See "XS_VER-
SION_BOOTCHECK".
XS_VERSION_BOOTCHECK
Macro to verify that a PM module’s $VERSION variable matches
the XS module’s "XS_VERSION" variable. This is usually handled
automatically by "xsubpp". See "The VERSIONCHECK: Keyword" in
perlxs.
XS_VERSION_BOOTCHECK;

Warning and Dieing

croak This is the XSUB-writer’s interface to Perl’s "die" function.
Normally call this function the same way you call the C
"printf" function. Calling "croak" returns control directly to
Perl, sidestepping the normal C order of execution. See "warn".
If you want to throw an exception object, assign the object to
$@ and then pass "Nullch" to croak():
errsv = get_sv("@", TRUE);
sv_setsv(errsv, exception_object);
croak(Nullch);
void croak(const char* pat, ...)
warn This is the XSUB-writer’s interface to Perl’s "warn" function.
Call this function the same way you call the C "printf" func-
tion. See "croak".
void warn(const char* pat, ...)

AUTHORS

Until May 1997, this document was maintained by Jeff Okamoto
<okamoto@corp.hp.com>. It is now maintained as part of Perl itself.
With lots of help and suggestions from Dean Roehrich, Malcolm Beattie,
Andreas Koenig, Paul Hudson, Ilya Zakharevich, Paul Marquess, Neil Bow-
ers, Matthew Green, Tim Bunce, Spider Boardman, Ulrich Pfeifer, Stephen
McCamant, and Gurusamy Sarathy.
API Listing originally by Dean Roehrich <roehrich@cray.com>.
Updated to be autogenerated from comments in the source by Benjamin
Stuhl.